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* [patch v16 0/4] JTAG driver introduction
From: Oleksandr Shamray @ 2018-01-12 16:54 UTC (permalink / raw)
  To: linux-arm-kernel

When a need raise up to use JTAG interface for system's devices
programming or CPU debugging, usually the user layer
application implements jtag protocol by bit-bang or using a 
proprietary connection to vendor hardware.
This method can be slow and not generic.
 
We propose to implement general JTAG interface and infrastructure
to communicate with user layer application. In such way, we can
have the standard JTAG interface core part and separation from
specific HW implementation.
This allow new capability to debug the CPU or program system's 
device via BMC without additional devices nor cost. 

This patch purpose is to add JTAG master core infrastructure by 
defining new JTAG class and provide generic JTAG interface
to allow hardware specific drivers to connect this interface.
This will enable all JTAG drivers to use the common interface
part and will have separate for hardware implementation.

The JTAG (Joint Test Action Group) core driver provides minimal generic
JTAG interface, which can be used by hardware specific JTAG master
controllers. By providing common interface for the JTAG controllers,
user space device programing is hardware independent.
 
Modern SoC which in use for embedded system' equipped with
internal JTAG master interface.
This interface is used for programming and debugging system's
hardware components, like CPLD, FPGA, CPU, voltage and
industrial controllers.
Firmware for such devices can be upgraded through JTAG interface during
Runtime. The JTAG standard support for multiple devices programming,
is in case their lines are daisy-chained together.

For example, systems which equipped with host CPU, BMC SoC or/and 
number of programmable devices are capable to connect a pin and
select system components dynamically for programming and debugging,
This is using by the BMC which is equipped with internal SoC master
controller.
For example:

BMC JTAG master --> pin selected to CPLDs chain for programming (filed
upgrade, production) 
BMC JTAG master --> pin selected to voltage monitors for programming 
(field upgrade, production) 
BMC JTAG master --> pin selected to host CPU (on-site debugging 
and developers debugging)

For example, we can have application in user space which using calls
to JTAG driver executes CPLD programming directly from SVF file
 
The JTAG standard (IEEE 1149.1) defines the next connector pins:
- TDI (Test Data In);
- TDO (Test Data Out);
- TCK (Test Clock);
- TMS (Test Mode Select);
- TRST (Test Reset) (Optional);

The SoC equipped with JTAG master controller, performs
device programming on command or vector level. For example
a file in a standard SVF (Serial Vector Format) that contains
boundary scan vectors, can be used by sending each vector
to the JTAG interface and the JTAG controller will execute
the programming.

Initial version provides the system calls set for:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
  number of clocks.

SoC which are not equipped with JTAG master interface, can be built
on top of JTAG core driver infrastructure, by applying bit-banging of
TDI, TDO, TCK and TMS pins within the hardware specific driver.

Linus Torvalds (1):
  Linux 4.15-rc6

Oleksandr Shamray (3):
  drivers: jtag: Add JTAG core driver
  drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master
    driver
  Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx
    families     JTAG master driver

 .../devicetree/bindings/jtag/aspeed-jtag.txt       |   22 +
 Documentation/ioctl/ioctl-number.txt               |    2 +
 MAINTAINERS                                        |   10 +
 Makefile                                           |    2 +-
 drivers/Kconfig                                    |    2 +
 drivers/Makefile                                   |    1 +
 drivers/jtag/Kconfig                               |   30 +
 drivers/jtag/Makefile                              |    2 +
 drivers/jtag/jtag-aspeed.c                         |  786 ++++++++++++++++++++
 drivers/jtag/jtag.c                                |  283 +++++++
 include/linux/jtag.h                               |   41 +
 include/uapi/linux/jtag.h                          |  104 +++
 12 files changed, 1284 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
 create mode 100644 drivers/jtag/Kconfig
 create mode 100644 drivers/jtag/Makefile
 create mode 100644 drivers/jtag/jtag-aspeed.c
 create mode 100644 drivers/jtag/jtag.c
 create mode 100644 include/linux/jtag.h
 create mode 100644 include/uapi/linux/jtag.h

^ permalink raw reply

* [patch v16 1/4] Linux 4.15-rc6
From: Oleksandr Shamray @ 2018-01-12 16:54 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776101-25482-1-git-send-email-oleksandrs@mellanox.com>

From: Linus Torvalds <torvalds@linux-foundation.org>

---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 92b74bc..eb1f597 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 VERSION = 4
 PATCHLEVEL = 15
 SUBLEVEL = 0
-EXTRAVERSION = -rc5
+EXTRAVERSION = -rc6
 NAME = Fearless Coyote
 
 # *DOCUMENTATION*
-- 
1.7.1

^ permalink raw reply related

* [patch v16 2/4] drivers: jtag: Add JTAG core driver
From: Oleksandr Shamray @ 2018-01-12 16:54 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776101-25482-1-git-send-email-oleksandrs@mellanox.com>

Initial patch for JTAG driver
JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.

Driver exposes set of IOCTL to user space for:
- XFER:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
  number of clocks).
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.

Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;

Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
---
v15->v16
Commen ts pointed by Florian Fainelli <f.fainelli@gmail.com>
- move check jtag->ops->* in ioctl before get_user()
- change error type -EINVAL --> -EBUSY on open already opened jtag
- remove unnecessary ARCH_DMA_MINALIGN flag from kzalloc
- remove define ARCH_DMA_MINALIGN

v14->v15
v13->v14
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change style of head block comment from /**/ to //

v12->v13
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change jtag.c licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description
v11->v12
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change jtag.h licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description

Chip Bilbrey <chip@bilbrey.org>
- Remove Apeed reference from uapi jtag.h header
- Remove access mode from xfer and idle transactions
- Add new ioctl JTAG_SIOCMODE for set hw mode
- Add only one open per JTAG port blocking with mutex blocking

v10->v11
Notifications from kbuild test robot <lkp@intel.com>
- include types.h headeri to jtag.h
- fix incompatible type of xfer callback
- remove rdundant class defination
- Fix return order in case of xfer error

V9->v10
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- remove unnecessary alignment for pirv data
- move jtag_copy_to_user and jtag_copy_from_user code just to ioctl
- move int jtag_run_test_idle_op and jtag_xfer_op code
  just to ioctl
- change return error codes to more applicable
- add missing error checks
- fix error check order in ioctl
- remove unnecessary blank lines
- add param validation to ioctl
- remove compat_ioctl
- remove only one open per JTAG port blocking.
  User will care about this.
- Fix idr memory leak on jtag_exit
- change cdev device type to misc

V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype

v7->v8
Comments pointed by Moritz Fischer <moritz.fischer@ettus.com>
- Fix misspelling s/friver/driver

v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c

v5->v6
v4->v5

v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type  to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle

v2->v3
Notifications from kbuild test robot <lkp@intel.com>
- Change include path to <linux/types.h> in jtag.h

v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig

Comments pointed by Andrew Lunn <andrew@lunn.ch>
- Change list_add_tail in jtag_unregister to list_del

Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add SPDX-License-Identifier instead of license text

Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data

Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
 Documentation/ioctl/ioctl-number.txt |    2 +
 MAINTAINERS                          |   10 ++
 drivers/Kconfig                      |    2 +
 drivers/Makefile                     |    1 +
 drivers/jtag/Kconfig                 |   16 ++
 drivers/jtag/Makefile                |    1 +
 drivers/jtag/jtag.c                  |  283 ++++++++++++++++++++++++++++++++++
 include/linux/jtag.h                 |   41 +++++
 include/uapi/linux/jtag.h            |  104 +++++++++++++
 9 files changed, 460 insertions(+), 0 deletions(-)
 create mode 100644 drivers/jtag/Kconfig
 create mode 100644 drivers/jtag/Makefile
 create mode 100644 drivers/jtag/jtag.c
 create mode 100644 include/linux/jtag.h
 create mode 100644 include/uapi/linux/jtag.h

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae..1af2508 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -321,6 +321,8 @@ Code  Seq#(hex)	Include File		Comments
 0xB0	all	RATIO devices		in development:
 					<mailto:vgo@ratio.de>
 0xB1	00-1F	PPPoX			<mailto:mostrows@styx.uwaterloo.ca>
+0xB2	00-0f	linux/jtag.h		JTAG driver
+					<mailto:oleksandrs@mellanox.com>
 0xB3	00	linux/mmc/ioctl.h
 0xB4	00-0F	linux/gpio.h		<mailto:linux-gpio@vger.kernel.org>
 0xB5	00-0F	uapi/linux/rpmsg.h	<mailto:linux-remoteproc@vger.kernel.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index b46c9ce..42aac3a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7513,6 +7513,16 @@ L:	linux-serial at vger.kernel.org
 S:	Maintained
 F:	drivers/tty/serial/jsm/
 
+JTAG SUBSYSTEM
+M:	Oleksandr Shamray <oleksandrs@mellanox.com>
+M:	Vadim Pasternak <vadimp@mellanox.com>
+S:	Maintained
+F:	include/linux/jtag.h
+F:	include/uapi/linux/jtag.h
+F:	drivers/jtag/
+F:	Documentation/devicetree/bindings/jtag/
+F:	Documentation/ABI/testing/jtag-cdev
+
 K10TEMP HARDWARE MONITORING DRIVER
 M:	Clemens Ladisch <clemens@ladisch.de>
 L:	linux-hwmon at vger.kernel.org
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 152744c..414a34b 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -211,4 +211,6 @@ source "drivers/mux/Kconfig"
 
 source "drivers/opp/Kconfig"
 
+source "drivers/jtag/Kconfig"
+
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index e06f7f6..6d50f74 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -184,3 +184,4 @@ obj-$(CONFIG_FPGA)		+= fpga/
 obj-$(CONFIG_FSI)		+= fsi/
 obj-$(CONFIG_TEE)		+= tee/
 obj-$(CONFIG_MULTIPLEXER)	+= mux/
+obj-$(CONFIG_JTAG)		+= jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..0fad1a3
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,16 @@
+menuconfig JTAG
+	tristate "JTAG support"
+	---help---
+	  This provides basic core functionality support for jtag class devices
+	  Hardware equipped with JTAG microcontroller which can be built
+	  on top of this drivers. Driver exposes the set of IOCTL to the
+	  user space for:
+	  SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
+	  SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
+	  RUNTEST (Forces IEEE 1149.1 bus to a run state for specified
+	  number of clocks).
+
+	  If you want this support, you should say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG)		+= jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..91ce263
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+// drivers/jtag/jtag.c
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define JTAG_NAME	"jtag0"
+#define MAX_JTAG_NAME_LEN (sizeof("jtag") + 5)
+
+struct jtag {
+	struct miscdevice miscdev;
+	struct device *dev;
+	const struct jtag_ops *ops;
+	int id;
+	bool opened;
+	struct mutex open_lock;
+	unsigned long priv[0];
+};
+
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+	return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct jtag *jtag = file->private_data;
+	struct jtag_run_test_idle idle;
+	struct jtag_xfer xfer;
+	u8 *xfer_data;
+	u32 data_size;
+	u32 value;
+	int err;
+
+	if (!arg)
+		return -EINVAL;
+
+	switch (cmd) {
+	case JTAG_GIOCFREQ:
+		if (!jtag->ops->freq_get)
+			err = -EOPNOTSUPP;
+
+		err = jtag->ops->freq_get(jtag, &value);
+		if (err)
+			break;
+
+		if (put_user(value, (__u32 *)arg))
+			err = -EFAULT;
+		break;
+
+	case JTAG_SIOCFREQ:
+		if (!jtag->ops->freq_set)
+			return -EOPNOTSUPP;
+
+		if (get_user(value, (__u32 *)arg))
+			return -EFAULT;
+		if (value == 0)
+			return -EINVAL;
+
+		err = jtag->ops->freq_set(jtag, value);
+		break;
+
+	case JTAG_IOCRUNTEST:
+		if (!jtag->ops->idle)
+			return -EOPNOTSUPP;
+
+		if (copy_from_user(&idle, (void *)arg,
+				   sizeof(struct jtag_run_test_idle)))
+			return -EFAULT;
+
+		if (idle.endstate > JTAG_STATE_PAUSEDR)
+			return -EINVAL;
+
+		err = jtag->ops->idle(jtag, &idle);
+		break;
+
+	case JTAG_IOCXFER:
+		if (!jtag->ops->xfer)
+			return -EOPNOTSUPP;
+
+		if (copy_from_user(&xfer, (void *)arg,
+				   sizeof(struct jtag_xfer)))
+			return -EFAULT;
+
+		if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+			return -EINVAL;
+
+		if (xfer.type > JTAG_SDR_XFER)
+			return -EINVAL;
+
+		if (xfer.direction > JTAG_WRITE_XFER)
+			return -EINVAL;
+
+		if (xfer.endstate > JTAG_STATE_PAUSEDR)
+			return -EINVAL;
+
+		data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE);
+		xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), data_size);
+
+		if (!xfer_data)
+			return -EFAULT;
+
+		err = jtag->ops->xfer(jtag, &xfer, xfer_data);
+		if (err) {
+			kfree(xfer_data);
+			return -EFAULT;
+		}
+
+		err = copy_to_user(u64_to_user_ptr(xfer.tdio),
+				   (void *)(xfer_data), data_size);
+
+		if (err) {
+			kfree(xfer_data);
+			return -EFAULT;
+		}
+
+		kfree(xfer_data);
+		if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
+			return -EFAULT;
+		break;
+
+	case JTAG_GIOCSTATUS:
+		if (!jtag->ops->status_get)
+			return -EOPNOTSUPP;
+
+		err = jtag->ops->status_get(jtag, &value);
+		if (err)
+			break;
+
+		err = put_user(value, (__u32 *)arg);
+		if (err)
+			err = -EFAULT;
+		break;
+	case JTAG_SIOCMODE:
+		if (!jtag->ops->mode_set)
+			return  -EOPNOTSUPP;
+
+		if (get_user(value, (__u32 *)arg))
+			return -EFAULT;
+		if (value == 0)
+			return -EINVAL;
+
+		err = jtag->ops->mode_set(jtag, value);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return err;
+}
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = container_of(file->private_data, struct jtag,
+					 miscdev);
+
+	if (mutex_lock_interruptible(&jtag->open_lock))
+		return -ERESTARTSYS;
+
+	if (jtag->opened) {
+		mutex_unlock(&jtag->open_lock);
+		return -EBUSY;
+	}
+
+	nonseekable_open(inode, file);
+	file->private_data = jtag;
+	jtag->opened = true;
+	mutex_unlock(&jtag->open_lock);
+	return 0;
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = file->private_data;
+
+	mutex_lock(&jtag->open_lock);
+	jtag->opened = false;
+	mutex_unlock(&jtag->open_lock);
+	return 0;
+}
+
+static const struct file_operations jtag_fops = {
+	.owner		= THIS_MODULE,
+	.open		= jtag_open,
+	.release	= jtag_release,
+	.llseek		= noop_llseek,
+	.unlocked_ioctl = jtag_ioctl,
+};
+
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
+{
+	struct jtag *jtag;
+
+	jtag = kzalloc(sizeof(*jtag), GFP_KERNEL);
+	if (!jtag)
+		return NULL;
+
+	jtag->ops = ops;
+	return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+	kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+int jtag_register(struct jtag *jtag)
+{
+	char *name;
+	int err;
+	int id;
+
+	id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+	if (id < 0)
+		return id;
+
+	jtag->id = id;
+
+	name = kzalloc(MAX_JTAG_NAME_LEN, GFP_KERNEL);
+	if (!name) {
+		err = -ENOMEM;
+		goto err_jtag_alloc;
+	}
+
+	err = snprintf(name, MAX_JTAG_NAME_LEN, "jtag%d", id);
+	if (err < 0)
+		goto err_jtag_name;
+
+	mutex_init(&jtag->open_lock);
+	jtag->miscdev.fops =  &jtag_fops;
+	jtag->miscdev.minor = MISC_DYNAMIC_MINOR;
+	jtag->miscdev.name = name;
+
+	err = misc_register(&jtag->miscdev);
+	if (err)
+		dev_err(jtag->dev, "Unable to register device\n");
+	else
+		return 0;
+	jtag->opened = false;
+
+err_jtag_name:
+	kfree(name);
+err_jtag_alloc:
+	ida_simple_remove(&jtag_ida, id);
+	return err;
+}
+EXPORT_SYMBOL_GPL(jtag_register);
+
+void jtag_unregister(struct jtag *jtag)
+{
+	misc_deregister(&jtag->miscdev);
+	kfree(jtag->miscdev.name);
+	ida_simple_remove(&jtag_ida, jtag->id);
+}
+EXPORT_SYMBOL_GPL(jtag_unregister);
+
+static void __exit jtag_exit(void)
+{
+	ida_destroy(&jtag_ida);
+}
+
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..918cfe0
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+// include/linux/jtag.h - JTAG class driver
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#ifndef __JTAG_H
+#define __JTAG_H
+
+#include <uapi/linux/jtag.h>
+
+#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for jtag control functions:
+ *
+ * @freq_get: get frequency function. Filled by device driver
+ * @freq_set: set frequency function. Filled by device driver
+ * @status_get: set status function. Filled by device driver
+ * @idle: set JTAG to idle state function. Filled by device driver
+ * @xfer: send JTAG xfer function. Filled by device driver
+ */
+struct jtag_ops {
+	int (*freq_get)(struct jtag *jtag, u32 *freq);
+	int (*freq_set)(struct jtag *jtag, u32 freq);
+	int (*status_get)(struct jtag *jtag, u32 *state);
+	int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
+	int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer, u8 *xfer_data);
+	int (*mode_set)(struct jtag *jtag, u32 mode_mask);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int jtag_register(struct jtag *jtag);
+void jtag_unregister(struct jtag *jtag);
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..cda2520
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+// include/uapi/linux/jtag.h - JTAG class driver uapi
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+#include <linux/types.h>
+/*
+ * JTAG_XFER_HW_MODE: JTAG hardware mode. Used to set HW drived or bitbang
+ * mode. This is bitmask param of ioctl JTAG_SIOCMODE command
+ */
+#define  JTAG_XFER_HW_MODE 1
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ */
+enum jtag_endstate {
+	JTAG_STATE_IDLE,
+	JTAG_STATE_PAUSEIR,
+	JTAG_STATE_PAUSEDR,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+	JTAG_SIR_XFER,
+	JTAG_SDR_XFER,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ */
+enum jtag_xfer_direction {
+	JTAG_READ_XFER,
+	JTAG_WRITE_XFER,
+};
+
+/**
+ * struct jtag_run_test_idle - forces JTAG state machine to
+ * RUN_TEST/IDLE state
+ *
+ * @reset: 0 - run IDLE/PAUSE from current state
+ *         1 - go through TEST_LOGIC/RESET state before  IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure represents interface to JTAG device for jtag idle
+ * execution.
+ */
+struct jtag_run_test_idle {
+	__u8	reset;
+	__u8	endstate;
+	__u8	tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure represents interface to JTAG device for jtag sdr xfer
+ * execution.
+ */
+struct jtag_xfer {
+	__u8	type;
+	__u8	direction;
+	__u8	endstate;
+	__u32	length;
+	__u64	tdio;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC	0xb2
+
+#define JTAG_IOCRUNTEST	_IOW(__JTAG_IOCTL_MAGIC, 0,\
+			     struct jtag_run_test_idle)
+#define JTAG_SIOCFREQ	_IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ	_IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER	_IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+#define JTAG_SIOCMODE	_IOW(__JTAG_IOCTL_MAGIC, 5, unsigned int)
+
+#define JTAG_FIRST_MINOR 0
+#define JTAG_MAX_DEVICES 32
+
+#endif /* __UAPI_LINUX_JTAG_H */
-- 
1.7.1

^ permalink raw reply related

* [patch v16 3/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver
From: Oleksandr Shamray @ 2018-01-12 16:55 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776101-25482-1-git-send-email-oleksandrs@mellanox.com>

Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.

Driver implements the following jtag ops:
- freq_get;
- freq_set;
- status_get;
- idle;
- xfer;

It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Joel Stanley <joel@jms.id.au>
---
v15->v16
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- Add reset_control on Jtag init/deinit

v14->v15
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- Add ARCH_ASPEED || COMPILE_TEST to Kconfig
- remove unused offset variable
- remove "aspeed_jtag" from dev_err and dev_dbg messages
- change clk_prepare_enable initialisation order

v13->v14
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change style of head block comment from /**/ to //

v12->v13
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change jtag-aspeed.c licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description
Comments pointed by Kun Yi <kunyi@google.com>
- Changed capability check for aspeed,ast2400-jtag/ast200-jtag

v11->v12
Comments pointed by Chip Bilbrey <chip@bilbrey.org>
- Remove access mode from xfer and idle transactions
- Add new ioctl JTAG_SIOCMODE for set hw mode

v10->v11
v9->v10
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- add *data parameter to xfer function prototype

v7->v8
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- aspeed_jtag_init replace goto to return;
- change input variables type from __u32 to u32
  in functios freq_get, freq_set, status_get
- change sm_ variables type from char to u8
- in jatg_init add disable clocks on error case
- remove release_mem_region on error case
- remove devm_free_irq on jtag_deinit
- Fix misspelling Disabe/Disable
- Change compatible string to ast2400 and ast2000

v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Add include <linux/types.h> to jtag-asapeed.c

v5->v6
v4->v5
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Added HAS_IOMEM dependence in Kconfig to avoid
  "undefined reference to `devm_ioremap_resource'" error,
  because in some arch this not supported

v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type  to __u64
- change internal status type from enum to __u32

v2->v3

v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- change license type from GPLv2/BSD to GPLv2

Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
- Change .compatible to soc-specific compatible names
  aspeed,aspeed4000-jtag/aspeed5000-jtag
- Added dt-bindings

Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Reorder functions and removed the forward declarations
- Add static const qualifier to state machine states transitions
- Change .compatible to soc-specific compatible names
  aspeed,aspeed4000-jtag/aspeed5000-jtag
- Add dt-bindings

Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- Change module name jtag-aspeed in description in Kconfig

Comments pointed by kbuild test robot <lkp@intel.com>
- Remove invalid include <asm/mach-types.h>
- add resource_size instead of calculation
---
 drivers/jtag/Kconfig       |   14 +
 drivers/jtag/Makefile      |    1 +
 drivers/jtag/jtag-aspeed.c |  785 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 800 insertions(+), 0 deletions(-)
 create mode 100644 drivers/jtag/jtag-aspeed.c

diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
index 0fad1a3..63ddf1f 100644
--- a/drivers/jtag/Kconfig
+++ b/drivers/jtag/Kconfig
@@ -14,3 +14,17 @@ menuconfig JTAG
 
 	  To compile this driver as a module, choose M here: the module will
 	  be called jtag.
+
+menuconfig JTAG_ASPEED
+	tristate "Aspeed SoC JTAG controller support"
+	depends on JTAG && HAS_IOMEM
+	depends on ARCH_ASPEED || COMPILE_TEST
+	---help---
+	  This provides a support for Aspeed JTAG device, equipped on
+	  Aspeed SoC 24xx and 25xx families. Drivers allows programming
+	  of hardware devices, connected to SoC through the JTAG interface.
+
+	  If you want this support, you should say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called jtag-aspeed.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
index af37493..04a855e 100644
--- a/drivers/jtag/Makefile
+++ b/drivers/jtag/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_JTAG)		+= jtag.o
+obj-$(CONFIG_JTAG_ASPEED)	+= jtag-aspeed.o
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
new file mode 100644
index 0000000..9cbd6da
--- /dev/null
+++ b/drivers/jtag/jtag-aspeed.c
@@ -0,0 +1,785 @@
+// SPDX-License-Identifier: GPL-2.0
+// drivers/jtag/aspeed-jtag.c
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define ASPEED_JTAG_DATA		0x00
+#define ASPEED_JTAG_INST		0x04
+#define ASPEED_JTAG_CTRL		0x08
+#define ASPEED_JTAG_ISR			0x0C
+#define ASPEED_JTAG_SW			0x10
+#define ASPEED_JTAG_TCK			0x14
+#define ASPEED_JTAG_EC			0x18
+
+#define ASPEED_JTAG_DATA_MSB		0x01
+#define ASPEED_JTAG_DATA_CHUNK_SIZE	0x20
+
+/* ASPEED_JTAG_CTRL: Engine Control */
+#define ASPEED_JTAG_CTL_ENG_EN		BIT(31)
+#define ASPEED_JTAG_CTL_ENG_OUT_EN	BIT(30)
+#define ASPEED_JTAG_CTL_FORCE_TMS	BIT(29)
+#define ASPEED_JTAG_CTL_INST_LEN(x)	((x) << 20)
+#define ASPEED_JTAG_CTL_LASPEED_INST	BIT(17)
+#define ASPEED_JTAG_CTL_INST_EN		BIT(16)
+#define ASPEED_JTAG_CTL_DR_UPDATE	BIT(10)
+#define ASPEED_JTAG_CTL_DATA_LEN(x)	((x) << 4)
+#define ASPEED_JTAG_CTL_LASPEED_DATA	BIT(1)
+#define ASPEED_JTAG_CTL_DATA_EN		BIT(0)
+
+/* ASPEED_JTAG_ISR : Interrupt status and enable */
+#define ASPEED_JTAG_ISR_INST_PAUSE	BIT(19)
+#define ASPEED_JTAG_ISR_INST_COMPLETE	BIT(18)
+#define ASPEED_JTAG_ISR_DATA_PAUSE	BIT(17)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE	BIT(16)
+#define ASPEED_JTAG_ISR_INST_PAUSE_EN	BIT(3)
+#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
+#define ASPEED_JTAG_ISR_DATA_PAUSE_EN	BIT(1)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
+#define ASPEED_JTAG_ISR_INT_EN_MASK	GENMASK(3, 0)
+#define ASPEED_JTAG_ISR_INT_MASK	GENMASK(19, 16)
+
+/* ASPEED_JTAG_SW : Software Mode and Status */
+#define ASPEED_JTAG_SW_MODE_EN		BIT(19)
+#define ASPEED_JTAG_SW_MODE_TCK		BIT(18)
+#define ASPEED_JTAG_SW_MODE_TMS		BIT(17)
+#define ASPEED_JTAG_SW_MODE_TDIO	BIT(16)
+
+/* ASPEED_JTAG_TCK : TCK Control */
+#define ASPEED_JTAG_TCK_DIVISOR_MASK	GENMASK(10, 0)
+#define ASPEED_JTAG_TCK_GET_DIV(x)	((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
+
+/* ASPEED_JTAG_EC : Controller set for go to IDLE */
+#define ASPEED_JTAG_EC_GO_IDLE		BIT(0)
+
+#define ASPEED_JTAG_IOUT_LEN(len)	(ASPEED_JTAG_CTL_ENG_EN |\
+					 ASPEED_JTAG_CTL_ENG_OUT_EN |\
+					 ASPEED_JTAG_CTL_INST_LEN(len))
+
+#define ASPEED_JTAG_DOUT_LEN(len)	(ASPEED_JTAG_CTL_ENG_EN |\
+					 ASPEED_JTAG_CTL_ENG_OUT_EN |\
+					 ASPEED_JTAG_CTL_DATA_LEN(len))
+
+#define ASPEED_JTAG_TCK_WAIT		10
+#define ASPEED_JTAG_RESET_CNTR		10
+
+#define ASPEED_JTAG_NAME		"jtag-aspeed"
+
+struct aspeed_jtag {
+	void __iomem			*reg_base;
+	struct device			*dev;
+	struct clk			*pclk;
+	enum jtag_endstate		status;
+	int				irq;
+	struct reset_control		*rst;
+	u32				flag;
+	wait_queue_head_t		jtag_wq;
+	u32				mode;
+};
+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+	return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+	writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	unsigned long apb_frq;
+	u32 tck_val;
+	u16 div;
+
+	apb_frq = clk_get_rate(aspeed_jtag->pclk);
+	div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+	tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+	aspeed_jtag_write(aspeed_jtag,
+			  (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+			  ASPEED_JTAG_TCK);
+	return 0;
+}
+
+static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	u32 pclk;
+	u32 tck;
+
+	pclk = clk_get_rate(aspeed_jtag->pclk);
+	tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+	*frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
+
+	return 0;
+}
+
+static int aspeed_jtag_mode_set(struct jtag *jtag, u32 mode)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	aspeed_jtag->mode = mode;
+	return 0;
+}
+
+static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
+{
+	int i;
+
+	for (i = 0; i < cnt; i++)
+		aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
+}
+
+static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
+				  u8 tms, u8 tdi)
+{
+	char tdo = 0;
+
+	/* TCK = 0 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+	aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+	/* TCK = 1 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TCK |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+	if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
+	    ASPEED_JTAG_SW_MODE_TDIO)
+		tdo = 1;
+
+	aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+	/* TCK = 0 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+	return tdo;
+}
+
+static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_INST_PAUSE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
+}
+
+static void
+aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_INST_COMPLETE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
+}
+
+static void
+aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_DATA_PAUSE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
+}
+
+static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_DATA_COMPLETE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
+}
+
+static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
+				 int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
+}
+
+static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
+					 struct jtag_run_test_idle *runtest)
+{
+	static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
+	static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
+	static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
+	static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
+	static const u8 sm_pause_idle[] = {1, 1, 0};
+	int i;
+
+	/* SW mode from idle/pause-> to pause/idle */
+	if (runtest->reset) {
+		for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
+			aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
+	}
+
+	switch (aspeed_jtag->status) {
+	case JTAG_STATE_IDLE:
+		switch (runtest->endstate) {
+		case JTAG_STATE_PAUSEIR:
+			/* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
+					     sizeof(sm_idle_irpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+			break;
+		case JTAG_STATE_PAUSEDR:
+			/* ->DRSCan->DRCap->DRExit1->PauseDR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
+					     sizeof(sm_idle_drpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+			break;
+		case JTAG_STATE_IDLE:
+			/* IDLE */
+			aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+			aspeed_jtag->status = JTAG_STATE_IDLE;
+			break;
+		default:
+			break;
+		}
+		break;
+
+	case JTAG_STATE_PAUSEIR:
+	/* Fall-through */
+	case JTAG_STATE_PAUSEDR:
+		/* From IR/DR Pause */
+		switch (runtest->endstate) {
+		case JTAG_STATE_PAUSEIR:
+			/*
+			 * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
+			 * IRExit1->PauseIR
+			 */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
+					     sizeof(sm_pause_irpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+			break;
+		case JTAG_STATE_PAUSEDR:
+			/*
+			 * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
+			 * DRExit1->PauseDR
+			 */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
+					     sizeof(sm_pause_drpause));
+			aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+			break;
+		case JTAG_STATE_IDLE:
+			/* to Exit2 IR/DR->Updt IR/DR->IDLE */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+					     sizeof(sm_pause_idle));
+			aspeed_jtag->status = JTAG_STATE_IDLE;
+			break;
+		default:
+			break;
+		}
+		break;
+
+	default:
+		dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
+		break;
+	}
+
+	/* Stay on IDLE for at least  TCK cycle */
+	for (i = 0; i < runtest->tck; i++)
+		aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+}
+
+/**
+ * aspeed_jtag_run_test_idle:
+ * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
+ * devices into Run-Test/Idle State.
+ */
+static int aspeed_jtag_idle(struct jtag *jtag,
+			    struct jtag_run_test_idle *runtest)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	dev_dbg(aspeed_jtag->dev, "runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
+		aspeed_jtag->status,
+		aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
+		end_status_str[runtest->endstate], runtest->reset,
+		runtest->tck);
+
+	if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
+		aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
+		return 0;
+	}
+
+	/* Disable sw mode */
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+	/* x TMS high + 1 TMS low */
+	if (runtest->reset)
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+				  ASPEED_JTAG_CTL_ENG_OUT_EN |
+				  ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
+	else
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
+				  ASPEED_JTAG_EC);
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+	aspeed_jtag->status = JTAG_STATE_IDLE;
+	return 0;
+}
+
+static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
+				struct jtag_xfer *xfer, unsigned long *data)
+{
+	unsigned long remain_xfer = xfer->length;
+	unsigned long shift_bits = 0;
+	unsigned long index = 0;
+	unsigned long tdi;
+	char          tdo;
+
+	if (xfer->direction == JTAG_READ_XFER)
+		tdi = UINT_MAX;
+	else
+		tdi = data[index];
+
+	while (remain_xfer > 1) {
+		tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
+					    tdi & ASPEED_JTAG_DATA_MSB);
+		data[index] |= tdo << (shift_bits %
+					    ASPEED_JTAG_DATA_CHUNK_SIZE);
+
+		tdi >>= 1;
+		shift_bits++;
+		remain_xfer--;
+
+		if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
+			dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
+				index, data[index]);
+
+			tdo = 0;
+			index++;
+
+			if (xfer->direction == JTAG_READ_XFER)
+				tdi = UINT_MAX;
+			else
+				tdi = data[index];
+		}
+	}
+
+	tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
+	data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
+}
+
+static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
+				       enum jtag_xfer_type type, u32 bits_len)
+{
+	dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
+
+	if (type == JTAG_SIR_XFER) {
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
+				  ASPEED_JTAG_CTRL);
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+				  ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
+	} else {
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
+				  ASPEED_JTAG_CTRL);
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+				  ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
+	}
+}
+
+static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
+					    enum jtag_xfer_type type,
+					    u32 shift_bits,
+					    enum jtag_endstate endstate)
+{
+	if (endstate != JTAG_STATE_IDLE) {
+		if (type == JTAG_SIR_XFER) {
+			dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits),
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_INST_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_instruction_pause(aspeed_jtag);
+		} else {
+			dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_DR_UPDATE,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_DR_UPDATE |
+					  ASPEED_JTAG_CTL_DATA_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
+		}
+	} else {
+		if (type == JTAG_SIR_XFER) {
+			dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_INST,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_INST |
+					  ASPEED_JTAG_CTL_INST_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_instruction_complete(aspeed_jtag);
+		} else {
+			dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_DATA,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_DATA |
+					  ASPEED_JTAG_CTL_DATA_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_data_complete(aspeed_jtag);
+		}
+	}
+}
+
+static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
+				struct jtag_xfer *xfer, unsigned long *data)
+{
+	unsigned long remain_xfer = xfer->length;
+	unsigned long index = 0;
+	char shift_bits;
+	u32 data_reg;
+
+	data_reg = xfer->type == JTAG_SIR_XFER ?
+		   ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
+	while (remain_xfer) {
+		if (xfer->direction == JTAG_WRITE_XFER) {
+			dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
+				index, data[index]);
+
+			aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
+		} else {
+			aspeed_jtag_write(aspeed_jtag, 0, data_reg);
+		}
+
+		if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
+			shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
+
+			/*
+			 * Read bytes were not equals to column length
+			 * and go to Pause-DR
+			 */
+			aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
+						   shift_bits);
+		} else {
+			/*
+			 * Read bytes equals to column length =>
+			 * Update-DR
+			 */
+			shift_bits = remain_xfer;
+			aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
+							shift_bits,
+							xfer->endstate);
+		}
+
+		if (xfer->direction == JTAG_READ_XFER) {
+			if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
+				data[index] = aspeed_jtag_read(aspeed_jtag,
+							       data_reg);
+
+				data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
+								shift_bits;
+			} else {
+				data[index] = aspeed_jtag_read(aspeed_jtag,
+							       data_reg);
+			}
+			dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
+				index, data[index]);
+		}
+
+		remain_xfer = remain_xfer - shift_bits;
+		index++;
+		dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
+	}
+}
+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+			    u8 *xfer_data)
+{
+	static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+	static const u8 sm_update_shiftdr[] = {1, 0, 0};
+	static const u8 sm_pause_idle[] = {1, 1, 0};
+	static const u8 sm_pause_update[] = {1, 1};
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	unsigned long *data = (unsigned long *)xfer_data;
+	unsigned long remain_xfer = xfer->length;
+	char dbg_str[256];
+	int pos = 0;
+	int i;
+
+	for (i = 0; i <= xfer->length / BITS_PER_BYTE; i++) {
+		pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+				"0x%02x ", xfer_data[i]);
+	}
+
+	dev_dbg(aspeed_jtag->dev, " %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+		xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+		xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+		aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
+		xfer->endstate, remain_xfer, dbg_str);
+
+	if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
+		/* SW mode */
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+				  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+		if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+			/*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+					     sizeof(sm_pause_update));
+		}
+
+		if (xfer->type == JTAG_SIR_XFER)
+			/* ->IRSCan->CapIR->ShiftIR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+					     sizeof(sm_update_shiftir));
+		else
+			/* ->DRScan->DRCap->DRShift */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+					     sizeof(sm_update_shiftdr));
+
+		aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+		/* DIPause/DRPause */
+		aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+		if (xfer->endstate == JTAG_STATE_IDLE) {
+			/* ->DRExit2->DRUpdate->IDLE */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+					     sizeof(sm_pause_idle));
+		}
+	} else {
+		/* hw mode */
+		aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+		aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+	}
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+	aspeed_jtag->status = xfer->endstate;
+	return 0;
+}
+
+static int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	*status = aspeed_jtag->status;
+	return 0;
+}
+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+	struct aspeed_jtag *aspeed_jtag = dev_id;
+	irqreturn_t ret;
+	u32 status;
+
+	status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+	dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+	if (status & ASPEED_JTAG_ISR_INT_MASK) {
+		aspeed_jtag_write(aspeed_jtag,
+				  (status & ASPEED_JTAG_ISR_INT_MASK)
+				  | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+				  ASPEED_JTAG_ISR);
+		aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+	}
+
+	if (aspeed_jtag->flag) {
+		wake_up_interruptible(&aspeed_jtag->jtag_wq);
+		ret = IRQ_HANDLED;
+	} else {
+		dev_err(aspeed_jtag->dev, "irq status:%x\n",
+			status);
+		ret = IRQ_NONE;
+	}
+	return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+		     struct aspeed_jtag *aspeed_jtag)
+{
+	struct resource *res;
+	int err;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+	if (IS_ERR(aspeed_jtag->reg_base))
+		return -ENOMEM;
+
+	aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+	if (IS_ERR(aspeed_jtag->pclk)) {
+		dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+		return PTR_ERR(aspeed_jtag->pclk);
+	}
+
+	aspeed_jtag->irq = platform_get_irq(pdev, 0);
+	if (aspeed_jtag->irq < 0) {
+		dev_err(aspeed_jtag->dev, "no irq specified\n");
+		return -ENOENT;
+	}
+
+	clk_prepare_enable(aspeed_jtag->pclk);
+
+	aspeed_jtag->rst = devm_reset_control_get_shared(aspeed_jtag->dev,
+							 NULL);
+	if (IS_ERR(aspeed_jtag->rst)) {
+		dev_err(aspeed_jtag->dev,
+			"missing or invalid reset controller device tree entry");
+		return PTR_ERR(aspeed_jtag->rst);
+	}
+	reset_control_deassert(aspeed_jtag->rst);
+
+	/* Enable clock */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+			  ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+	err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+			       aspeed_jtag_interrupt, 0,
+			       "aspeed-jtag", aspeed_jtag);
+	if (err) {
+		dev_err(aspeed_jtag->dev, "unable to get IRQ");
+		goto clk_unprep;
+	}
+	dev_dbg(&pdev->dev, "IRQ %d.\n", aspeed_jtag->irq);
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+			  ASPEED_JTAG_ISR_INST_COMPLETE |
+			  ASPEED_JTAG_ISR_DATA_PAUSE |
+			  ASPEED_JTAG_ISR_DATA_COMPLETE |
+			  ASPEED_JTAG_ISR_INST_PAUSE_EN |
+			  ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+			  ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+			  ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+			  ASPEED_JTAG_ISR);
+
+	aspeed_jtag->flag = 0;
+	aspeed_jtag->mode = 0;
+	init_waitqueue_head(&aspeed_jtag->jtag_wq);
+	return 0;
+
+clk_unprep:
+	clk_disable_unprepare(aspeed_jtag->pclk);
+	return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+		       struct aspeed_jtag *aspeed_jtag)
+{
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+	/* Disable clock */
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+	reset_control_assert(aspeed_jtag->rst);
+	clk_disable_unprepare(aspeed_jtag->pclk);
+	return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+	.freq_get = aspeed_jtag_freq_get,
+	.freq_set = aspeed_jtag_freq_set,
+	.status_get = aspeed_jtag_status_get,
+	.idle = aspeed_jtag_idle,
+	.xfer = aspeed_jtag_xfer,
+	.mode_set = aspeed_jtag_mode_set
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+	struct aspeed_jtag *aspeed_jtag;
+	struct device *dev;
+	struct jtag *jtag;
+	int err;
+
+	dev = &pdev->dev;
+	jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+	if (!jtag)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, jtag);
+	aspeed_jtag = jtag_priv(jtag);
+	aspeed_jtag->dev = &pdev->dev;
+
+	/* Initialize device*/
+	err = aspeed_jtag_init(pdev, aspeed_jtag);
+	if (err)
+		goto err_jtag_init;
+
+	/* Initialize JTAG core structure*/
+	err = jtag_register(jtag);
+	if (err)
+		goto err_jtag_register;
+
+	return 0;
+
+err_jtag_register:
+	aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+	jtag_free(jtag);
+	return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+	struct jtag *jtag;
+
+	jtag = platform_get_drvdata(pdev);
+	aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+	jtag_unregister(jtag);
+	jtag_free(jtag);
+	return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+	{ .compatible = "aspeed,ast2400-jtag", },
+	{ .compatible = "aspeed,ast2500-jtag", },
+	{}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+	.probe = aspeed_jtag_probe,
+	.remove = aspeed_jtag_remove,
+	.driver = {
+		.name = ASPEED_JTAG_NAME,
+		.of_match_table = aspeed_jtag_of_match,
+	},
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.1

^ permalink raw reply related

* [patch v16 4/4] Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx families JTAG master driver
From: Oleksandr Shamray @ 2018-01-12 16:55 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776101-25482-1-git-send-email-oleksandrs@mellanox.com>

It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Rob Herring <robh@kernel.org>
---
v15->v16
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- change clocks = <&clk_apb> to proper clocks = <&syscon ASPEED_CLK_APB>
- add reset descriptions in bndings file

v14->v15
v13->v14
v12->v13
v11->v12
v10->v11
v9->v10
v8->v9
v7->v8
Comments pointed by pointed by Joel Stanley <joel.stan@gmail.com>
- Change compatible string to ast2400 and ast2000

V6->v7
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
 - Fix spell "Doccumentation" -> "Documentation"

v5->v6
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Small nit: s/documentation/Documentation/

v4->v5

V3->v4
Comments pointed by Rob Herring <robh@kernel.org>
- delete unnecessary "status" and "reg-shift" descriptions in
  bndings file

v2->v3
Comments pointed by Rob Herring <robh@kernel.org>
- split Aspeed jtag driver and binding to sepatrate patches
- delete unnecessary "status" and "reg-shift" descriptions in
  bndings file
---
 .../devicetree/bindings/jtag/aspeed-jtag.txt       |   22 ++++++++++++++++++++
 drivers/jtag/jtag-aspeed.c                         |    1 +
 2 files changed, 23 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt

diff --git a/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
new file mode 100644
index 0000000..7c36eb6
--- /dev/null
+++ b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
@@ -0,0 +1,22 @@
+Aspeed JTAG driver for ast2400 and ast2500 SoC
+
+Required properties:
+- compatible:		Should be one of
+      - "aspeed,ast2400-jtag"
+      - "aspeed,ast2500-jtag"
+- reg			contains the offset and length of the JTAG memory
+			region
+- clocks		root clock of bus, should reference the APB
+			clock in the second cell
+- resets		phandle to reset controller with the reset number in
+			the second cell
+- interrupts		should contain JTAG controller interrupt
+
+Example:
+jtag: jtag at 1e6e4000 {
+	compatible = "aspeed,ast2500-jtag";
+	reg = <0x1e6e4000 0x1c>;
+	clocks = <&syscon ASPEED_CLK_APB>;
+	resets = <&syscon ASPEED_RESET_JTAG_MASTER>;
+	interrupts = <43>;
+};
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
index 9cbd6da..f679041 100644
--- a/drivers/jtag/jtag-aspeed.c
+++ b/drivers/jtag/jtag-aspeed.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <uapi/linux/jtag.h>
-- 
1.7.1

^ permalink raw reply related

* [patch v16 1/4] Linux 4.15-rc6
From: Oleksandr Shamray @ 2018-01-12 17:01 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776101-25482-2-git-send-email-oleksandrs@mellanox.com>

do not pay attention about this.

Best Regards,
Oleksandr Shamray

> -----Original Message-----
> From: Oleksandr Shamray [mailto:oleksandrs at mellanox.com]
> Sent: 12 ?????? 2018 ?. 18:55
> To: gregkh at linuxfoundation.org; arnd at arndb.de
> Cc: linux-kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
> devicetree at vger.kernel.org; openbmc at lists.ozlabs.org; joel at jms.id.au;
> jiri at resnulli.us; tklauser at distanz.ch; linux-serial at vger.kernel.org; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level at mellanox.com>; robh+dt at kernel.org; openocd-devel-
> owner at lists.sourceforge.net; linux-api at vger.kernel.org;
> davem at davemloft.net; mchehab at kernel.org; Linus Torvalds
> <torvalds@linux-foundation.org>
> Subject: [patch v16 1/4] Linux 4.15-rc6
> 
> From: Linus Torvalds <torvalds@linux-foundation.org>
> 
> ---
>  Makefile |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 92b74bc..eb1f597 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -2,7 +2,7 @@
>  VERSION = 4
>  PATCHLEVEL = 15
>  SUBLEVEL = 0
> -EXTRAVERSION = -rc5
> +EXTRAVERSION = -rc6
>  NAME = Fearless Coyote
> 
>  # *DOCUMENTATION*
> --
> 1.7.1

^ permalink raw reply

* [patch v16 0/4] JTAG driver introduction
From: Oleksandr Shamray @ 2018-01-12 17:08 UTC (permalink / raw)
  To: linux-arm-kernel

When a need raise up to use JTAG interface for system's devices
programming or CPU debugging, usually the user layer
application implements jtag protocol by bit-bang or using a 
proprietary connection to vendor hardware.
This method can be slow and not generic.
 
We propose to implement general JTAG interface and infrastructure
to communicate with user layer application. In such way, we can
have the standard JTAG interface core part and separation from
specific HW implementation.
This allow new capability to debug the CPU or program system's 
device via BMC without additional devices nor cost. 

This patch purpose is to add JTAG master core infrastructure by 
defining new JTAG class and provide generic JTAG interface
to allow hardware specific drivers to connect this interface.
This will enable all JTAG drivers to use the common interface
part and will have separate for hardware implementation.

The JTAG (Joint Test Action Group) core driver provides minimal generic
JTAG interface, which can be used by hardware specific JTAG master
controllers. By providing common interface for the JTAG controllers,
user space device programing is hardware independent.
 
Modern SoC which in use for embedded system' equipped with
internal JTAG master interface.
This interface is used for programming and debugging system's
hardware components, like CPLD, FPGA, CPU, voltage and
industrial controllers.
Firmware for such devices can be upgraded through JTAG interface during
Runtime. The JTAG standard support for multiple devices programming,
is in case their lines are daisy-chained together.

For example, systems which equipped with host CPU, BMC SoC or/and 
number of programmable devices are capable to connect a pin and
select system components dynamically for programming and debugging,
This is using by the BMC which is equipped with internal SoC master
controller.
For example:

BMC JTAG master --> pin selected to CPLDs chain for programming (filed
upgrade, production) 
BMC JTAG master --> pin selected to voltage monitors for programming 
(field upgrade, production) 
BMC JTAG master --> pin selected to host CPU (on-site debugging 
and developers debugging)

For example, we can have application in user space which using calls
to JTAG driver executes CPLD programming directly from SVF file
 
The JTAG standard (IEEE 1149.1) defines the next connector pins:
- TDI (Test Data In);
- TDO (Test Data Out);
- TCK (Test Clock);
- TMS (Test Mode Select);
- TRST (Test Reset) (Optional);

The SoC equipped with JTAG master controller, performs
device programming on command or vector level. For example
a file in a standard SVF (Serial Vector Format) that contains
boundary scan vectors, can be used by sending each vector
to the JTAG interface and the JTAG controller will execute
the programming.

Initial version provides the system calls set for:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
  number of clocks.

SoC which are not equipped with JTAG master interface, can be built
on top of JTAG core driver infrastructure, by applying bit-banging of
TDI, TDO, TCK and TMS pins within the hardware specific driver.

Oleksandr Shamray (4):
  drivers: jtag: Add JTAG core driver
  drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master
    driver
  Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx
    families     JTAG master driver
  Documentation: jtag: Add ABI documentation

 Documentation/ABI/testing/jtag-dev                 |   27 +
 .../devicetree/bindings/jtag/aspeed-jtag.txt       |   22 +
 Documentation/ioctl/ioctl-number.txt               |    2 +
 MAINTAINERS                                        |   10 +
 drivers/Kconfig                                    |    2 +
 drivers/Makefile                                   |    1 +
 drivers/jtag/Kconfig                               |   30 +
 drivers/jtag/Makefile                              |    2 +
 drivers/jtag/jtag-aspeed.c                         |  786 ++++++++++++++++++++
 drivers/jtag/jtag.c                                |  283 +++++++
 include/linux/jtag.h                               |   41 +
 include/uapi/linux/jtag.h                          |  104 +++
 12 files changed, 1310 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/ABI/testing/jtag-dev
 create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
 create mode 100644 drivers/jtag/Kconfig
 create mode 100644 drivers/jtag/Makefile
 create mode 100644 drivers/jtag/jtag-aspeed.c
 create mode 100644 drivers/jtag/jtag.c
 create mode 100644 include/linux/jtag.h
 create mode 100644 include/uapi/linux/jtag.h

^ permalink raw reply

* [patch v16 1/4] drivers: jtag: Add JTAG core driver
From: Oleksandr Shamray @ 2018-01-12 17:08 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776909-29894-1-git-send-email-oleksandrs@mellanox.com>

Initial patch for JTAG driver
JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.

Driver exposes set of IOCTL to user space for:
- XFER:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
  number of clocks).
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.

Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;

Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
---
v15->v16
Commen ts pointed by Florian Fainelli <f.fainelli@gmail.com>
- move check jtag->ops->* in ioctl before get_user()
- change error type -EINVAL --> -EBUSY on open already opened jtag
- remove unnecessary ARCH_DMA_MINALIGN flag from kzalloc
- remove define ARCH_DMA_MINALIGN

v14->v15
v13->v14
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change style of head block comment from /**/ to //

v12->v13
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change jtag.c licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description
v11->v12
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change jtag.h licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description

Chip Bilbrey <chip@bilbrey.org>
- Remove Apeed reference from uapi jtag.h header
- Remove access mode from xfer and idle transactions
- Add new ioctl JTAG_SIOCMODE for set hw mode
- Add only one open per JTAG port blocking with mutex blocking

v10->v11
Notifications from kbuild test robot <lkp@intel.com>
- include types.h headeri to jtag.h
- fix incompatible type of xfer callback
- remove rdundant class defination
- Fix return order in case of xfer error

V9->v10
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- remove unnecessary alignment for pirv data
- move jtag_copy_to_user and jtag_copy_from_user code just to ioctl
- move int jtag_run_test_idle_op and jtag_xfer_op code
  just to ioctl
- change return error codes to more applicable
- add missing error checks
- fix error check order in ioctl
- remove unnecessary blank lines
- add param validation to ioctl
- remove compat_ioctl
- remove only one open per JTAG port blocking.
  User will care about this.
- Fix idr memory leak on jtag_exit
- change cdev device type to misc

V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype

v7->v8
Comments pointed by Moritz Fischer <moritz.fischer@ettus.com>
- Fix misspelling s/friver/driver

v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c

v5->v6
v4->v5

v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type  to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle

v2->v3
Notifications from kbuild test robot <lkp@intel.com>
- Change include path to <linux/types.h> in jtag.h

v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig

Comments pointed by Andrew Lunn <andrew@lunn.ch>
- Change list_add_tail in jtag_unregister to list_del

Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add SPDX-License-Identifier instead of license text

Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data

Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
 Documentation/ioctl/ioctl-number.txt |    2 +
 MAINTAINERS                          |   10 ++
 drivers/Kconfig                      |    2 +
 drivers/Makefile                     |    1 +
 drivers/jtag/Kconfig                 |   16 ++
 drivers/jtag/Makefile                |    1 +
 drivers/jtag/jtag.c                  |  283 ++++++++++++++++++++++++++++++++++
 include/linux/jtag.h                 |   41 +++++
 include/uapi/linux/jtag.h            |  104 +++++++++++++
 9 files changed, 460 insertions(+), 0 deletions(-)
 create mode 100644 drivers/jtag/Kconfig
 create mode 100644 drivers/jtag/Makefile
 create mode 100644 drivers/jtag/jtag.c
 create mode 100644 include/linux/jtag.h
 create mode 100644 include/uapi/linux/jtag.h

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae..1af2508 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -321,6 +321,8 @@ Code  Seq#(hex)	Include File		Comments
 0xB0	all	RATIO devices		in development:
 					<mailto:vgo@ratio.de>
 0xB1	00-1F	PPPoX			<mailto:mostrows@styx.uwaterloo.ca>
+0xB2	00-0f	linux/jtag.h		JTAG driver
+					<mailto:oleksandrs@mellanox.com>
 0xB3	00	linux/mmc/ioctl.h
 0xB4	00-0F	linux/gpio.h		<mailto:linux-gpio@vger.kernel.org>
 0xB5	00-0F	uapi/linux/rpmsg.h	<mailto:linux-remoteproc@vger.kernel.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index b46c9ce..42aac3a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7513,6 +7513,16 @@ L:	linux-serial at vger.kernel.org
 S:	Maintained
 F:	drivers/tty/serial/jsm/
 
+JTAG SUBSYSTEM
+M:	Oleksandr Shamray <oleksandrs@mellanox.com>
+M:	Vadim Pasternak <vadimp@mellanox.com>
+S:	Maintained
+F:	include/linux/jtag.h
+F:	include/uapi/linux/jtag.h
+F:	drivers/jtag/
+F:	Documentation/devicetree/bindings/jtag/
+F:	Documentation/ABI/testing/jtag-cdev
+
 K10TEMP HARDWARE MONITORING DRIVER
 M:	Clemens Ladisch <clemens@ladisch.de>
 L:	linux-hwmon at vger.kernel.org
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 152744c..414a34b 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -211,4 +211,6 @@ source "drivers/mux/Kconfig"
 
 source "drivers/opp/Kconfig"
 
+source "drivers/jtag/Kconfig"
+
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index e06f7f6..6d50f74 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -184,3 +184,4 @@ obj-$(CONFIG_FPGA)		+= fpga/
 obj-$(CONFIG_FSI)		+= fsi/
 obj-$(CONFIG_TEE)		+= tee/
 obj-$(CONFIG_MULTIPLEXER)	+= mux/
+obj-$(CONFIG_JTAG)		+= jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..0fad1a3
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,16 @@
+menuconfig JTAG
+	tristate "JTAG support"
+	---help---
+	  This provides basic core functionality support for jtag class devices
+	  Hardware equipped with JTAG microcontroller which can be built
+	  on top of this drivers. Driver exposes the set of IOCTL to the
+	  user space for:
+	  SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
+	  SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
+	  RUNTEST (Forces IEEE 1149.1 bus to a run state for specified
+	  number of clocks).
+
+	  If you want this support, you should say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG)		+= jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..91ce263
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+// drivers/jtag/jtag.c
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define JTAG_NAME	"jtag0"
+#define MAX_JTAG_NAME_LEN (sizeof("jtag") + 5)
+
+struct jtag {
+	struct miscdevice miscdev;
+	struct device *dev;
+	const struct jtag_ops *ops;
+	int id;
+	bool opened;
+	struct mutex open_lock;
+	unsigned long priv[0];
+};
+
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+	return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct jtag *jtag = file->private_data;
+	struct jtag_run_test_idle idle;
+	struct jtag_xfer xfer;
+	u8 *xfer_data;
+	u32 data_size;
+	u32 value;
+	int err;
+
+	if (!arg)
+		return -EINVAL;
+
+	switch (cmd) {
+	case JTAG_GIOCFREQ:
+		if (!jtag->ops->freq_get)
+			err = -EOPNOTSUPP;
+
+		err = jtag->ops->freq_get(jtag, &value);
+		if (err)
+			break;
+
+		if (put_user(value, (__u32 *)arg))
+			err = -EFAULT;
+		break;
+
+	case JTAG_SIOCFREQ:
+		if (!jtag->ops->freq_set)
+			return -EOPNOTSUPP;
+
+		if (get_user(value, (__u32 *)arg))
+			return -EFAULT;
+		if (value == 0)
+			return -EINVAL;
+
+		err = jtag->ops->freq_set(jtag, value);
+		break;
+
+	case JTAG_IOCRUNTEST:
+		if (!jtag->ops->idle)
+			return -EOPNOTSUPP;
+
+		if (copy_from_user(&idle, (void *)arg,
+				   sizeof(struct jtag_run_test_idle)))
+			return -EFAULT;
+
+		if (idle.endstate > JTAG_STATE_PAUSEDR)
+			return -EINVAL;
+
+		err = jtag->ops->idle(jtag, &idle);
+		break;
+
+	case JTAG_IOCXFER:
+		if (!jtag->ops->xfer)
+			return -EOPNOTSUPP;
+
+		if (copy_from_user(&xfer, (void *)arg,
+				   sizeof(struct jtag_xfer)))
+			return -EFAULT;
+
+		if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+			return -EINVAL;
+
+		if (xfer.type > JTAG_SDR_XFER)
+			return -EINVAL;
+
+		if (xfer.direction > JTAG_WRITE_XFER)
+			return -EINVAL;
+
+		if (xfer.endstate > JTAG_STATE_PAUSEDR)
+			return -EINVAL;
+
+		data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE);
+		xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), data_size);
+
+		if (!xfer_data)
+			return -EFAULT;
+
+		err = jtag->ops->xfer(jtag, &xfer, xfer_data);
+		if (err) {
+			kfree(xfer_data);
+			return -EFAULT;
+		}
+
+		err = copy_to_user(u64_to_user_ptr(xfer.tdio),
+				   (void *)(xfer_data), data_size);
+
+		if (err) {
+			kfree(xfer_data);
+			return -EFAULT;
+		}
+
+		kfree(xfer_data);
+		if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
+			return -EFAULT;
+		break;
+
+	case JTAG_GIOCSTATUS:
+		if (!jtag->ops->status_get)
+			return -EOPNOTSUPP;
+
+		err = jtag->ops->status_get(jtag, &value);
+		if (err)
+			break;
+
+		err = put_user(value, (__u32 *)arg);
+		if (err)
+			err = -EFAULT;
+		break;
+	case JTAG_SIOCMODE:
+		if (!jtag->ops->mode_set)
+			return  -EOPNOTSUPP;
+
+		if (get_user(value, (__u32 *)arg))
+			return -EFAULT;
+		if (value == 0)
+			return -EINVAL;
+
+		err = jtag->ops->mode_set(jtag, value);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return err;
+}
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = container_of(file->private_data, struct jtag,
+					 miscdev);
+
+	if (mutex_lock_interruptible(&jtag->open_lock))
+		return -ERESTARTSYS;
+
+	if (jtag->opened) {
+		mutex_unlock(&jtag->open_lock);
+		return -EBUSY;
+	}
+
+	nonseekable_open(inode, file);
+	file->private_data = jtag;
+	jtag->opened = true;
+	mutex_unlock(&jtag->open_lock);
+	return 0;
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = file->private_data;
+
+	mutex_lock(&jtag->open_lock);
+	jtag->opened = false;
+	mutex_unlock(&jtag->open_lock);
+	return 0;
+}
+
+static const struct file_operations jtag_fops = {
+	.owner		= THIS_MODULE,
+	.open		= jtag_open,
+	.release	= jtag_release,
+	.llseek		= noop_llseek,
+	.unlocked_ioctl = jtag_ioctl,
+};
+
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
+{
+	struct jtag *jtag;
+
+	jtag = kzalloc(sizeof(*jtag), GFP_KERNEL);
+	if (!jtag)
+		return NULL;
+
+	jtag->ops = ops;
+	return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+	kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+int jtag_register(struct jtag *jtag)
+{
+	char *name;
+	int err;
+	int id;
+
+	id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+	if (id < 0)
+		return id;
+
+	jtag->id = id;
+
+	name = kzalloc(MAX_JTAG_NAME_LEN, GFP_KERNEL);
+	if (!name) {
+		err = -ENOMEM;
+		goto err_jtag_alloc;
+	}
+
+	err = snprintf(name, MAX_JTAG_NAME_LEN, "jtag%d", id);
+	if (err < 0)
+		goto err_jtag_name;
+
+	mutex_init(&jtag->open_lock);
+	jtag->miscdev.fops =  &jtag_fops;
+	jtag->miscdev.minor = MISC_DYNAMIC_MINOR;
+	jtag->miscdev.name = name;
+
+	err = misc_register(&jtag->miscdev);
+	if (err)
+		dev_err(jtag->dev, "Unable to register device\n");
+	else
+		return 0;
+	jtag->opened = false;
+
+err_jtag_name:
+	kfree(name);
+err_jtag_alloc:
+	ida_simple_remove(&jtag_ida, id);
+	return err;
+}
+EXPORT_SYMBOL_GPL(jtag_register);
+
+void jtag_unregister(struct jtag *jtag)
+{
+	misc_deregister(&jtag->miscdev);
+	kfree(jtag->miscdev.name);
+	ida_simple_remove(&jtag_ida, jtag->id);
+}
+EXPORT_SYMBOL_GPL(jtag_unregister);
+
+static void __exit jtag_exit(void)
+{
+	ida_destroy(&jtag_ida);
+}
+
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..918cfe0
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+// include/linux/jtag.h - JTAG class driver
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#ifndef __JTAG_H
+#define __JTAG_H
+
+#include <uapi/linux/jtag.h>
+
+#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for jtag control functions:
+ *
+ * @freq_get: get frequency function. Filled by device driver
+ * @freq_set: set frequency function. Filled by device driver
+ * @status_get: set status function. Filled by device driver
+ * @idle: set JTAG to idle state function. Filled by device driver
+ * @xfer: send JTAG xfer function. Filled by device driver
+ */
+struct jtag_ops {
+	int (*freq_get)(struct jtag *jtag, u32 *freq);
+	int (*freq_set)(struct jtag *jtag, u32 freq);
+	int (*status_get)(struct jtag *jtag, u32 *state);
+	int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
+	int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer, u8 *xfer_data);
+	int (*mode_set)(struct jtag *jtag, u32 mode_mask);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int jtag_register(struct jtag *jtag);
+void jtag_unregister(struct jtag *jtag);
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..cda2520
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+// include/uapi/linux/jtag.h - JTAG class driver uapi
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+#include <linux/types.h>
+/*
+ * JTAG_XFER_HW_MODE: JTAG hardware mode. Used to set HW drived or bitbang
+ * mode. This is bitmask param of ioctl JTAG_SIOCMODE command
+ */
+#define  JTAG_XFER_HW_MODE 1
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ */
+enum jtag_endstate {
+	JTAG_STATE_IDLE,
+	JTAG_STATE_PAUSEIR,
+	JTAG_STATE_PAUSEDR,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+	JTAG_SIR_XFER,
+	JTAG_SDR_XFER,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ */
+enum jtag_xfer_direction {
+	JTAG_READ_XFER,
+	JTAG_WRITE_XFER,
+};
+
+/**
+ * struct jtag_run_test_idle - forces JTAG state machine to
+ * RUN_TEST/IDLE state
+ *
+ * @reset: 0 - run IDLE/PAUSE from current state
+ *         1 - go through TEST_LOGIC/RESET state before  IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure represents interface to JTAG device for jtag idle
+ * execution.
+ */
+struct jtag_run_test_idle {
+	__u8	reset;
+	__u8	endstate;
+	__u8	tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure represents interface to JTAG device for jtag sdr xfer
+ * execution.
+ */
+struct jtag_xfer {
+	__u8	type;
+	__u8	direction;
+	__u8	endstate;
+	__u32	length;
+	__u64	tdio;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC	0xb2
+
+#define JTAG_IOCRUNTEST	_IOW(__JTAG_IOCTL_MAGIC, 0,\
+			     struct jtag_run_test_idle)
+#define JTAG_SIOCFREQ	_IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ	_IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER	_IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+#define JTAG_SIOCMODE	_IOW(__JTAG_IOCTL_MAGIC, 5, unsigned int)
+
+#define JTAG_FIRST_MINOR 0
+#define JTAG_MAX_DEVICES 32
+
+#endif /* __UAPI_LINUX_JTAG_H */
-- 
1.7.1

^ permalink raw reply related

* [patch v16 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver
From: Oleksandr Shamray @ 2018-01-12 17:08 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776909-29894-1-git-send-email-oleksandrs@mellanox.com>

Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.

Driver implements the following jtag ops:
- freq_get;
- freq_set;
- status_get;
- idle;
- xfer;

It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Joel Stanley <joel@jms.id.au>
---
v15->v16
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- Add reset_control on Jtag init/deinit

v14->v15
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- Add ARCH_ASPEED || COMPILE_TEST to Kconfig
- remove unused offset variable
- remove "aspeed_jtag" from dev_err and dev_dbg messages
- change clk_prepare_enable initialisation order

v13->v14
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change style of head block comment from /**/ to //

v12->v13
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change jtag-aspeed.c licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description
Comments pointed by Kun Yi <kunyi@google.com>
- Changed capability check for aspeed,ast2400-jtag/ast200-jtag

v11->v12
Comments pointed by Chip Bilbrey <chip@bilbrey.org>
- Remove access mode from xfer and idle transactions
- Add new ioctl JTAG_SIOCMODE for set hw mode

v10->v11
v9->v10
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- add *data parameter to xfer function prototype

v7->v8
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- aspeed_jtag_init replace goto to return;
- change input variables type from __u32 to u32
  in functios freq_get, freq_set, status_get
- change sm_ variables type from char to u8
- in jatg_init add disable clocks on error case
- remove release_mem_region on error case
- remove devm_free_irq on jtag_deinit
- Fix misspelling Disabe/Disable
- Change compatible string to ast2400 and ast2000

v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Add include <linux/types.h> to jtag-asapeed.c

v5->v6
v4->v5
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Added HAS_IOMEM dependence in Kconfig to avoid
  "undefined reference to `devm_ioremap_resource'" error,
  because in some arch this not supported

v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type  to __u64
- change internal status type from enum to __u32

v2->v3

v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- change license type from GPLv2/BSD to GPLv2

Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
- Change .compatible to soc-specific compatible names
  aspeed,aspeed4000-jtag/aspeed5000-jtag
- Added dt-bindings

Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Reorder functions and removed the forward declarations
- Add static const qualifier to state machine states transitions
- Change .compatible to soc-specific compatible names
  aspeed,aspeed4000-jtag/aspeed5000-jtag
- Add dt-bindings

Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- Change module name jtag-aspeed in description in Kconfig

Comments pointed by kbuild test robot <lkp@intel.com>
- Remove invalid include <asm/mach-types.h>
- add resource_size instead of calculation
---
 drivers/jtag/Kconfig       |   14 +
 drivers/jtag/Makefile      |    1 +
 drivers/jtag/jtag-aspeed.c |  785 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 800 insertions(+), 0 deletions(-)
 create mode 100644 drivers/jtag/jtag-aspeed.c

diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
index 0fad1a3..63ddf1f 100644
--- a/drivers/jtag/Kconfig
+++ b/drivers/jtag/Kconfig
@@ -14,3 +14,17 @@ menuconfig JTAG
 
 	  To compile this driver as a module, choose M here: the module will
 	  be called jtag.
+
+menuconfig JTAG_ASPEED
+	tristate "Aspeed SoC JTAG controller support"
+	depends on JTAG && HAS_IOMEM
+	depends on ARCH_ASPEED || COMPILE_TEST
+	---help---
+	  This provides a support for Aspeed JTAG device, equipped on
+	  Aspeed SoC 24xx and 25xx families. Drivers allows programming
+	  of hardware devices, connected to SoC through the JTAG interface.
+
+	  If you want this support, you should say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called jtag-aspeed.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
index af37493..04a855e 100644
--- a/drivers/jtag/Makefile
+++ b/drivers/jtag/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_JTAG)		+= jtag.o
+obj-$(CONFIG_JTAG_ASPEED)	+= jtag-aspeed.o
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
new file mode 100644
index 0000000..9cbd6da
--- /dev/null
+++ b/drivers/jtag/jtag-aspeed.c
@@ -0,0 +1,785 @@
+// SPDX-License-Identifier: GPL-2.0
+// drivers/jtag/aspeed-jtag.c
+//
+// Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define ASPEED_JTAG_DATA		0x00
+#define ASPEED_JTAG_INST		0x04
+#define ASPEED_JTAG_CTRL		0x08
+#define ASPEED_JTAG_ISR			0x0C
+#define ASPEED_JTAG_SW			0x10
+#define ASPEED_JTAG_TCK			0x14
+#define ASPEED_JTAG_EC			0x18
+
+#define ASPEED_JTAG_DATA_MSB		0x01
+#define ASPEED_JTAG_DATA_CHUNK_SIZE	0x20
+
+/* ASPEED_JTAG_CTRL: Engine Control */
+#define ASPEED_JTAG_CTL_ENG_EN		BIT(31)
+#define ASPEED_JTAG_CTL_ENG_OUT_EN	BIT(30)
+#define ASPEED_JTAG_CTL_FORCE_TMS	BIT(29)
+#define ASPEED_JTAG_CTL_INST_LEN(x)	((x) << 20)
+#define ASPEED_JTAG_CTL_LASPEED_INST	BIT(17)
+#define ASPEED_JTAG_CTL_INST_EN		BIT(16)
+#define ASPEED_JTAG_CTL_DR_UPDATE	BIT(10)
+#define ASPEED_JTAG_CTL_DATA_LEN(x)	((x) << 4)
+#define ASPEED_JTAG_CTL_LASPEED_DATA	BIT(1)
+#define ASPEED_JTAG_CTL_DATA_EN		BIT(0)
+
+/* ASPEED_JTAG_ISR : Interrupt status and enable */
+#define ASPEED_JTAG_ISR_INST_PAUSE	BIT(19)
+#define ASPEED_JTAG_ISR_INST_COMPLETE	BIT(18)
+#define ASPEED_JTAG_ISR_DATA_PAUSE	BIT(17)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE	BIT(16)
+#define ASPEED_JTAG_ISR_INST_PAUSE_EN	BIT(3)
+#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
+#define ASPEED_JTAG_ISR_DATA_PAUSE_EN	BIT(1)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
+#define ASPEED_JTAG_ISR_INT_EN_MASK	GENMASK(3, 0)
+#define ASPEED_JTAG_ISR_INT_MASK	GENMASK(19, 16)
+
+/* ASPEED_JTAG_SW : Software Mode and Status */
+#define ASPEED_JTAG_SW_MODE_EN		BIT(19)
+#define ASPEED_JTAG_SW_MODE_TCK		BIT(18)
+#define ASPEED_JTAG_SW_MODE_TMS		BIT(17)
+#define ASPEED_JTAG_SW_MODE_TDIO	BIT(16)
+
+/* ASPEED_JTAG_TCK : TCK Control */
+#define ASPEED_JTAG_TCK_DIVISOR_MASK	GENMASK(10, 0)
+#define ASPEED_JTAG_TCK_GET_DIV(x)	((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
+
+/* ASPEED_JTAG_EC : Controller set for go to IDLE */
+#define ASPEED_JTAG_EC_GO_IDLE		BIT(0)
+
+#define ASPEED_JTAG_IOUT_LEN(len)	(ASPEED_JTAG_CTL_ENG_EN |\
+					 ASPEED_JTAG_CTL_ENG_OUT_EN |\
+					 ASPEED_JTAG_CTL_INST_LEN(len))
+
+#define ASPEED_JTAG_DOUT_LEN(len)	(ASPEED_JTAG_CTL_ENG_EN |\
+					 ASPEED_JTAG_CTL_ENG_OUT_EN |\
+					 ASPEED_JTAG_CTL_DATA_LEN(len))
+
+#define ASPEED_JTAG_TCK_WAIT		10
+#define ASPEED_JTAG_RESET_CNTR		10
+
+#define ASPEED_JTAG_NAME		"jtag-aspeed"
+
+struct aspeed_jtag {
+	void __iomem			*reg_base;
+	struct device			*dev;
+	struct clk			*pclk;
+	enum jtag_endstate		status;
+	int				irq;
+	struct reset_control		*rst;
+	u32				flag;
+	wait_queue_head_t		jtag_wq;
+	u32				mode;
+};
+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+	return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+	writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	unsigned long apb_frq;
+	u32 tck_val;
+	u16 div;
+
+	apb_frq = clk_get_rate(aspeed_jtag->pclk);
+	div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+	tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+	aspeed_jtag_write(aspeed_jtag,
+			  (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+			  ASPEED_JTAG_TCK);
+	return 0;
+}
+
+static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	u32 pclk;
+	u32 tck;
+
+	pclk = clk_get_rate(aspeed_jtag->pclk);
+	tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+	*frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
+
+	return 0;
+}
+
+static int aspeed_jtag_mode_set(struct jtag *jtag, u32 mode)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	aspeed_jtag->mode = mode;
+	return 0;
+}
+
+static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
+{
+	int i;
+
+	for (i = 0; i < cnt; i++)
+		aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
+}
+
+static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
+				  u8 tms, u8 tdi)
+{
+	char tdo = 0;
+
+	/* TCK = 0 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+	aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+	/* TCK = 1 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TCK |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+	if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
+	    ASPEED_JTAG_SW_MODE_TDIO)
+		tdo = 1;
+
+	aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+	/* TCK = 0 */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  (tms * ASPEED_JTAG_SW_MODE_TMS) |
+			  (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+	return tdo;
+}
+
+static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_INST_PAUSE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
+}
+
+static void
+aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_INST_COMPLETE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
+}
+
+static void
+aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_DATA_PAUSE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
+}
+
+static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
+{
+	wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+				 ASPEED_JTAG_ISR_DATA_COMPLETE);
+	aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
+}
+
+static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
+				 int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
+}
+
+static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
+					 struct jtag_run_test_idle *runtest)
+{
+	static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
+	static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
+	static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
+	static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
+	static const u8 sm_pause_idle[] = {1, 1, 0};
+	int i;
+
+	/* SW mode from idle/pause-> to pause/idle */
+	if (runtest->reset) {
+		for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
+			aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
+	}
+
+	switch (aspeed_jtag->status) {
+	case JTAG_STATE_IDLE:
+		switch (runtest->endstate) {
+		case JTAG_STATE_PAUSEIR:
+			/* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
+					     sizeof(sm_idle_irpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+			break;
+		case JTAG_STATE_PAUSEDR:
+			/* ->DRSCan->DRCap->DRExit1->PauseDR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
+					     sizeof(sm_idle_drpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+			break;
+		case JTAG_STATE_IDLE:
+			/* IDLE */
+			aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+			aspeed_jtag->status = JTAG_STATE_IDLE;
+			break;
+		default:
+			break;
+		}
+		break;
+
+	case JTAG_STATE_PAUSEIR:
+	/* Fall-through */
+	case JTAG_STATE_PAUSEDR:
+		/* From IR/DR Pause */
+		switch (runtest->endstate) {
+		case JTAG_STATE_PAUSEIR:
+			/*
+			 * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
+			 * IRExit1->PauseIR
+			 */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
+					     sizeof(sm_pause_irpause));
+
+			aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+			break;
+		case JTAG_STATE_PAUSEDR:
+			/*
+			 * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
+			 * DRExit1->PauseDR
+			 */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
+					     sizeof(sm_pause_drpause));
+			aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+			break;
+		case JTAG_STATE_IDLE:
+			/* to Exit2 IR/DR->Updt IR/DR->IDLE */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+					     sizeof(sm_pause_idle));
+			aspeed_jtag->status = JTAG_STATE_IDLE;
+			break;
+		default:
+			break;
+		}
+		break;
+
+	default:
+		dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
+		break;
+	}
+
+	/* Stay on IDLE for at least  TCK cycle */
+	for (i = 0; i < runtest->tck; i++)
+		aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+}
+
+/**
+ * aspeed_jtag_run_test_idle:
+ * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
+ * devices into Run-Test/Idle State.
+ */
+static int aspeed_jtag_idle(struct jtag *jtag,
+			    struct jtag_run_test_idle *runtest)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	dev_dbg(aspeed_jtag->dev, "runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
+		aspeed_jtag->status,
+		aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
+		end_status_str[runtest->endstate], runtest->reset,
+		runtest->tck);
+
+	if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
+		aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
+		return 0;
+	}
+
+	/* Disable sw mode */
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+	/* x TMS high + 1 TMS low */
+	if (runtest->reset)
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+				  ASPEED_JTAG_CTL_ENG_OUT_EN |
+				  ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
+	else
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
+				  ASPEED_JTAG_EC);
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+	aspeed_jtag->status = JTAG_STATE_IDLE;
+	return 0;
+}
+
+static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
+				struct jtag_xfer *xfer, unsigned long *data)
+{
+	unsigned long remain_xfer = xfer->length;
+	unsigned long shift_bits = 0;
+	unsigned long index = 0;
+	unsigned long tdi;
+	char          tdo;
+
+	if (xfer->direction == JTAG_READ_XFER)
+		tdi = UINT_MAX;
+	else
+		tdi = data[index];
+
+	while (remain_xfer > 1) {
+		tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
+					    tdi & ASPEED_JTAG_DATA_MSB);
+		data[index] |= tdo << (shift_bits %
+					    ASPEED_JTAG_DATA_CHUNK_SIZE);
+
+		tdi >>= 1;
+		shift_bits++;
+		remain_xfer--;
+
+		if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
+			dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
+				index, data[index]);
+
+			tdo = 0;
+			index++;
+
+			if (xfer->direction == JTAG_READ_XFER)
+				tdi = UINT_MAX;
+			else
+				tdi = data[index];
+		}
+	}
+
+	tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
+	data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
+}
+
+static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
+				       enum jtag_xfer_type type, u32 bits_len)
+{
+	dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
+
+	if (type == JTAG_SIR_XFER) {
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
+				  ASPEED_JTAG_CTRL);
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+				  ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
+	} else {
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
+				  ASPEED_JTAG_CTRL);
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+				  ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
+	}
+}
+
+static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
+					    enum jtag_xfer_type type,
+					    u32 shift_bits,
+					    enum jtag_endstate endstate)
+{
+	if (endstate != JTAG_STATE_IDLE) {
+		if (type == JTAG_SIR_XFER) {
+			dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits),
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_INST_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_instruction_pause(aspeed_jtag);
+		} else {
+			dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_DR_UPDATE,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_DR_UPDATE |
+					  ASPEED_JTAG_CTL_DATA_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
+		}
+	} else {
+		if (type == JTAG_SIR_XFER) {
+			dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_INST,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_IOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_INST |
+					  ASPEED_JTAG_CTL_INST_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_instruction_complete(aspeed_jtag);
+		} else {
+			dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
+
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_DATA,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_write(aspeed_jtag,
+					  ASPEED_JTAG_DOUT_LEN(shift_bits) |
+					  ASPEED_JTAG_CTL_LASPEED_DATA |
+					  ASPEED_JTAG_CTL_DATA_EN,
+					  ASPEED_JTAG_CTRL);
+			aspeed_jtag_wait_data_complete(aspeed_jtag);
+		}
+	}
+}
+
+static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
+				struct jtag_xfer *xfer, unsigned long *data)
+{
+	unsigned long remain_xfer = xfer->length;
+	unsigned long index = 0;
+	char shift_bits;
+	u32 data_reg;
+
+	data_reg = xfer->type == JTAG_SIR_XFER ?
+		   ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
+	while (remain_xfer) {
+		if (xfer->direction == JTAG_WRITE_XFER) {
+			dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
+				index, data[index]);
+
+			aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
+		} else {
+			aspeed_jtag_write(aspeed_jtag, 0, data_reg);
+		}
+
+		if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
+			shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
+
+			/*
+			 * Read bytes were not equals to column length
+			 * and go to Pause-DR
+			 */
+			aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
+						   shift_bits);
+		} else {
+			/*
+			 * Read bytes equals to column length =>
+			 * Update-DR
+			 */
+			shift_bits = remain_xfer;
+			aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
+							shift_bits,
+							xfer->endstate);
+		}
+
+		if (xfer->direction == JTAG_READ_XFER) {
+			if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
+				data[index] = aspeed_jtag_read(aspeed_jtag,
+							       data_reg);
+
+				data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
+								shift_bits;
+			} else {
+				data[index] = aspeed_jtag_read(aspeed_jtag,
+							       data_reg);
+			}
+			dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
+				index, data[index]);
+		}
+
+		remain_xfer = remain_xfer - shift_bits;
+		index++;
+		dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
+	}
+}
+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+			    u8 *xfer_data)
+{
+	static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+	static const u8 sm_update_shiftdr[] = {1, 0, 0};
+	static const u8 sm_pause_idle[] = {1, 1, 0};
+	static const u8 sm_pause_update[] = {1, 1};
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+	unsigned long *data = (unsigned long *)xfer_data;
+	unsigned long remain_xfer = xfer->length;
+	char dbg_str[256];
+	int pos = 0;
+	int i;
+
+	for (i = 0; i <= xfer->length / BITS_PER_BYTE; i++) {
+		pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+				"0x%02x ", xfer_data[i]);
+	}
+
+	dev_dbg(aspeed_jtag->dev, " %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+		xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+		xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+		aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
+		xfer->endstate, remain_xfer, dbg_str);
+
+	if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
+		/* SW mode */
+		aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+				  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+		if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+			/*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+					     sizeof(sm_pause_update));
+		}
+
+		if (xfer->type == JTAG_SIR_XFER)
+			/* ->IRSCan->CapIR->ShiftIR */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+					     sizeof(sm_update_shiftir));
+		else
+			/* ->DRScan->DRCap->DRShift */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+					     sizeof(sm_update_shiftdr));
+
+		aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+		/* DIPause/DRPause */
+		aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+		if (xfer->endstate == JTAG_STATE_IDLE) {
+			/* ->DRExit2->DRUpdate->IDLE */
+			aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+					     sizeof(sm_pause_idle));
+		}
+	} else {
+		/* hw mode */
+		aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+		aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+	}
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+	aspeed_jtag->status = xfer->endstate;
+	return 0;
+}
+
+static int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
+{
+	struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+	*status = aspeed_jtag->status;
+	return 0;
+}
+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+	struct aspeed_jtag *aspeed_jtag = dev_id;
+	irqreturn_t ret;
+	u32 status;
+
+	status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+	dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+	if (status & ASPEED_JTAG_ISR_INT_MASK) {
+		aspeed_jtag_write(aspeed_jtag,
+				  (status & ASPEED_JTAG_ISR_INT_MASK)
+				  | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+				  ASPEED_JTAG_ISR);
+		aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+	}
+
+	if (aspeed_jtag->flag) {
+		wake_up_interruptible(&aspeed_jtag->jtag_wq);
+		ret = IRQ_HANDLED;
+	} else {
+		dev_err(aspeed_jtag->dev, "irq status:%x\n",
+			status);
+		ret = IRQ_NONE;
+	}
+	return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+		     struct aspeed_jtag *aspeed_jtag)
+{
+	struct resource *res;
+	int err;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+	if (IS_ERR(aspeed_jtag->reg_base))
+		return -ENOMEM;
+
+	aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+	if (IS_ERR(aspeed_jtag->pclk)) {
+		dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+		return PTR_ERR(aspeed_jtag->pclk);
+	}
+
+	aspeed_jtag->irq = platform_get_irq(pdev, 0);
+	if (aspeed_jtag->irq < 0) {
+		dev_err(aspeed_jtag->dev, "no irq specified\n");
+		return -ENOENT;
+	}
+
+	clk_prepare_enable(aspeed_jtag->pclk);
+
+	aspeed_jtag->rst = devm_reset_control_get_shared(aspeed_jtag->dev,
+							 NULL);
+	if (IS_ERR(aspeed_jtag->rst)) {
+		dev_err(aspeed_jtag->dev,
+			"missing or invalid reset controller device tree entry");
+		return PTR_ERR(aspeed_jtag->rst);
+	}
+	reset_control_deassert(aspeed_jtag->rst);
+
+	/* Enable clock */
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+			  ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+			  ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+	err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+			       aspeed_jtag_interrupt, 0,
+			       "aspeed-jtag", aspeed_jtag);
+	if (err) {
+		dev_err(aspeed_jtag->dev, "unable to get IRQ");
+		goto clk_unprep;
+	}
+	dev_dbg(&pdev->dev, "IRQ %d.\n", aspeed_jtag->irq);
+
+	aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+			  ASPEED_JTAG_ISR_INST_COMPLETE |
+			  ASPEED_JTAG_ISR_DATA_PAUSE |
+			  ASPEED_JTAG_ISR_DATA_COMPLETE |
+			  ASPEED_JTAG_ISR_INST_PAUSE_EN |
+			  ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+			  ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+			  ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+			  ASPEED_JTAG_ISR);
+
+	aspeed_jtag->flag = 0;
+	aspeed_jtag->mode = 0;
+	init_waitqueue_head(&aspeed_jtag->jtag_wq);
+	return 0;
+
+clk_unprep:
+	clk_disable_unprepare(aspeed_jtag->pclk);
+	return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+		       struct aspeed_jtag *aspeed_jtag)
+{
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+	/* Disable clock */
+	aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+	reset_control_assert(aspeed_jtag->rst);
+	clk_disable_unprepare(aspeed_jtag->pclk);
+	return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+	.freq_get = aspeed_jtag_freq_get,
+	.freq_set = aspeed_jtag_freq_set,
+	.status_get = aspeed_jtag_status_get,
+	.idle = aspeed_jtag_idle,
+	.xfer = aspeed_jtag_xfer,
+	.mode_set = aspeed_jtag_mode_set
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+	struct aspeed_jtag *aspeed_jtag;
+	struct device *dev;
+	struct jtag *jtag;
+	int err;
+
+	dev = &pdev->dev;
+	jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+	if (!jtag)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, jtag);
+	aspeed_jtag = jtag_priv(jtag);
+	aspeed_jtag->dev = &pdev->dev;
+
+	/* Initialize device*/
+	err = aspeed_jtag_init(pdev, aspeed_jtag);
+	if (err)
+		goto err_jtag_init;
+
+	/* Initialize JTAG core structure*/
+	err = jtag_register(jtag);
+	if (err)
+		goto err_jtag_register;
+
+	return 0;
+
+err_jtag_register:
+	aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+	jtag_free(jtag);
+	return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+	struct jtag *jtag;
+
+	jtag = platform_get_drvdata(pdev);
+	aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+	jtag_unregister(jtag);
+	jtag_free(jtag);
+	return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+	{ .compatible = "aspeed,ast2400-jtag", },
+	{ .compatible = "aspeed,ast2500-jtag", },
+	{}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+	.probe = aspeed_jtag_probe,
+	.remove = aspeed_jtag_remove,
+	.driver = {
+		.name = ASPEED_JTAG_NAME,
+		.of_match_table = aspeed_jtag_of_match,
+	},
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.1

^ permalink raw reply related

* [patch v16 3/4] Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx families JTAG master driver
From: Oleksandr Shamray @ 2018-01-12 17:08 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776909-29894-1-git-send-email-oleksandrs@mellanox.com>

It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Rob Herring <robh@kernel.org>
---
v15->v16
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- change clocks = <&clk_apb> to proper clocks = <&syscon ASPEED_CLK_APB>
- add reset descriptions in bndings file

v14->v15
v13->v14
v12->v13
v11->v12
v10->v11
v9->v10
v8->v9
v7->v8
Comments pointed by pointed by Joel Stanley <joel.stan@gmail.com>
- Change compatible string to ast2400 and ast2000

V6->v7
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
 - Fix spell "Doccumentation" -> "Documentation"

v5->v6
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Small nit: s/documentation/Documentation/

v4->v5

V3->v4
Comments pointed by Rob Herring <robh@kernel.org>
- delete unnecessary "status" and "reg-shift" descriptions in
  bndings file

v2->v3
Comments pointed by Rob Herring <robh@kernel.org>
- split Aspeed jtag driver and binding to sepatrate patches
- delete unnecessary "status" and "reg-shift" descriptions in
  bndings file
---
 .../devicetree/bindings/jtag/aspeed-jtag.txt       |   22 ++++++++++++++++++++
 drivers/jtag/jtag-aspeed.c                         |    1 +
 2 files changed, 23 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt

diff --git a/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
new file mode 100644
index 0000000..7c36eb6
--- /dev/null
+++ b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
@@ -0,0 +1,22 @@
+Aspeed JTAG driver for ast2400 and ast2500 SoC
+
+Required properties:
+- compatible:		Should be one of
+      - "aspeed,ast2400-jtag"
+      - "aspeed,ast2500-jtag"
+- reg			contains the offset and length of the JTAG memory
+			region
+- clocks		root clock of bus, should reference the APB
+			clock in the second cell
+- resets		phandle to reset controller with the reset number in
+			the second cell
+- interrupts		should contain JTAG controller interrupt
+
+Example:
+jtag: jtag at 1e6e4000 {
+	compatible = "aspeed,ast2500-jtag";
+	reg = <0x1e6e4000 0x1c>;
+	clocks = <&syscon ASPEED_CLK_APB>;
+	resets = <&syscon ASPEED_RESET_JTAG_MASTER>;
+	interrupts = <43>;
+};
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
index 9cbd6da..f679041 100644
--- a/drivers/jtag/jtag-aspeed.c
+++ b/drivers/jtag/jtag-aspeed.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <uapi/linux/jtag.h>
-- 
1.7.1

^ permalink raw reply related

* [patch v16 4/4] Documentation: jtag: Add ABI documentation
From: Oleksandr Shamray @ 2018-01-12 17:08 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515776909-29894-1-git-send-email-oleksandrs@mellanox.com>

Added document that describe the ABI for JTAG class drivrer

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
v15->v16
v14->v15
v13->v14
v12->v13
v11->v12
Tobias Klauser <tklauser@distanz.ch>
- rename /Documentation/ABI/testing/jatg-dev -> jtag-dev
- Typo: s/interfase/interface
v10->v11
v9->v10
Fixes added by Oleksandr:
- change jtag-cdev to jtag-dev in documentation
- update Kernel Version and Date in jtag-dev documentation;
v8->v9
v7->v8
v6->v7
Comments pointed by Pavel Machek <pavel@ucw.cz>
- Added jtag-cdev documentation to Documentation/ABI/testing folder
---
 Documentation/ABI/testing/jtag-dev |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/ABI/testing/jtag-dev

diff --git a/Documentation/ABI/testing/jtag-dev b/Documentation/ABI/testing/jtag-dev
new file mode 100644
index 0000000..cea9552
--- /dev/null
+++ b/Documentation/ABI/testing/jtag-dev
@@ -0,0 +1,27 @@
+What:		/dev/jtag[0-9]+
+Date:		October 2017
+KernelVersion:	4.17
+Contact:	oleksandrs at mellanox.com
+Description:
+		The misc device files /dev/jtag* are the interface
+		between JTAG master interface and userspace.
+
+		The ioctl(2)-based ABI is defined and documented in
+		[include/uapi]<linux/jtag.h>.
+
+		The following file operations are supported:
+
+		open(2)
+		The argument flag currently support only one access
+		mode O_RDWR.
+
+		ioctl(2)
+		Initiate various actions.
+		See the inline documentation in [include/uapi]<linux/jtag.h>
+		for descriptions of all ioctls.
+
+		close(2)
+		Stops and free up the I/O contexts that was associated
+		with the file descriptor.
+
+Users:		TBD
\ No newline at end of file
-- 
1.7.1

^ permalink raw reply related

* EDAC driver for ARMv8 L1/L2 cache
From: Borislav Petkov @ 2018-01-12 17:12 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <VI1PR04MB20786CC3E2981C0F60E095079A170@VI1PR04MB2078.eurprd04.prod.outlook.com>

On Fri, Jan 12, 2018 at 04:48:05PM +0000, York Sun wrote:
> I see Stratix10 has A53 core. I am concerned on reading the
> CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
> registers. They may not be available on all SoCs, or all time.

Is there something like CPUID on x86, on ARM64 which denotes presence of
a certain feature?

Or is that thing devicetree?

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

^ permalink raw reply

* EDAC driver for ARMv8 L1/L2 cache
From: York Sun @ 2018-01-12 17:17 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180112171251.4ricaz3lzditr7pi@pd.tnic>

On 01/12/2018 09:13 AM, Borislav Petkov wrote:
> On Fri, Jan 12, 2018 at 04:48:05PM +0000, York Sun wrote:
>> I see Stratix10 has A53 core. I am concerned on reading the
>> CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
>> registers. They may not be available on all SoCs, or all time.
> 
> Is there something like CPUID on x86, on ARM64 which denotes presence of
> a certain feature?
> 
> Or is that thing devicetree?
> 

This feature is available on the SoC I am working on (NXP LS1046A). It
seems always there. I don't know if there is any register denoting the
existence of such feature. I guess we can use device tree if this
feature exists. Not sure if big.LITTLE is a concern here.

York

^ permalink raw reply

* [PATCH] usb: mtu3: fix semicolon.cocci warnings
From: kbuild test robot @ 2018-01-12 17:18 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <201801130147.bQuKjq5V%fengguang.wu@intel.com>

From: Fengguang Wu <fengguang.wu@intel.com>

drivers/usb/mtu3/mtu3_host.c:58:2-3: Unneeded semicolon


 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: f0ede2c6282b ("usb: mtu3: supports remote wakeup for mt2712 with two SSUSB IPs")
CC: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
---

 mtu3_host.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/mtu3/mtu3_host.c
+++ b/drivers/usb/mtu3/mtu3_host.c
@@ -55,7 +55,7 @@ static void ssusb_wakeup_ip_sleep_set(st
 		break;
 	default:
 		return;
-	};
+	}
 	regmap_update_bits(ssusb->uwk, reg, msk, val);
 }
 

^ permalink raw reply

* EDAC driver for ARMv8 L1/L2 cache
From: Mark Rutland @ 2018-01-12 17:23 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180112171251.4ricaz3lzditr7pi@pd.tnic>

On Fri, Jan 12, 2018 at 06:12:51PM +0100, Borislav Petkov wrote:
> On Fri, Jan 12, 2018 at 04:48:05PM +0000, York Sun wrote:
> > I see Stratix10 has A53 core. I am concerned on reading the
> > CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
> > registers. They may not be available on all SoCs, or all time.
> 
> Is there something like CPUID on x86, on ARM64 which denotes presence of
> a certain feature?
> 
> Or is that thing devicetree?

We have ID registers, like CPUID, but for various reasons those aren't
sufficient to guarantee that IMPLEMENTATION DEFINED features can be
used.

If we want to support this, we'd certainly need something in DT.

For ACPI systems I'd expect this to be hidden behind APEI or similar,
with the kernel staying well clear of these registers.

Thanks,
Mark.

^ permalink raw reply

* [PATCH] phy: work around 'phys' references to usb-nop-xceiv devices
From: Stefan Wahren @ 2018-01-12 17:37 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180112101223.3661181-1-arnd@arndb.de>

[add some potential testers]

> Arnd Bergmann <arnd@arndb.de> hat am 12. Januar 2018 um 11:12 geschrieben:
> 
> 
> Stefan Wahren reports a problem with a warning fix that was merged
> for v4.15: we had lots of device nodes with a 'phys' property pointing
> to a device node that is not compliant with the binding documented in
> Documentation/devicetree/bindings/phy/phy-bindings.txt
> 
> This generally works because USB HCD drivers that support both the generic
> phy subsystem and the older usb-phy subsystem ignore most errors from
> phy_get() and related calls and then use the usb-phy driver instead.
> 
> However, it turns out that making the usb-nop-xceiv device compatible with
> the generic-phy binding changes the phy_get() return code from -EINVAL to
> -EPROBE_DEFER, and the dwc2 usb controller driver for bcm2835 now returns
> -EPROBE_DEFER from its probe function rather than ignoring the failure,
> breaking all USB support on raspberry-pi when CONFIG_GENERIC_PHY is
> enabled. The same code is used in the dwc3 driver and the usb_add_hcd()
> function, so a reasonable assumption would be that many other platforms
> are affected as well.
> 
> I have reviewed all the related patches and concluded that "usb-nop-xceiv"
> is the only USB phy that is affected by the change, and since it is by far
> the most commonly referenced phy, all the other USB phy drivers appear
> to be used in ways that are are either safe in DT (they don't use the
> 'phys' property), or in the driver (they already ignore -EPROBE_DEFER
> from generic-phy when usb-phy is available).
> 
> To work around the problem, this adds a special case to _of_phy_get()
> so we ignore any PHY node that is compatible with "usb-nop-xceiv",
> as we know that this can never load no matter how much we defer. In the
> future, we might implement a generic-phy driver for "usb-nop-xceiv"
> and then remove this workaround.
> 
> Since we generally want older kernels to also want to work with the
> fixed devicetree files, it would be good to backport the patch into
> stable kernels as well (3.13+ are possibly affected), even though they
> don't contain any of the patches that may have caused regressions.
> 
> Fixes: 014d6da6cb25 ARM: dts: bcm283x: Fix DTC warnings about missing phy-cells
> Fixes: c5bbf358b790 arm: dts: nspire: Add missing #phy-cells to usb-nop-xceiv
> Fixes: 44e5dced2ef6 arm: dts: marvell: Add missing #phy-cells to usb-nop-xceiv
> Fixes: f568f6f554b8 ARM: dts: omap: Add missing #phy-cells to usb-nop-xceiv
> Fixes: d745d5f277bf ARM: dts: imx51-zii-rdu1: Add missing #phy-cells to usb-nop-xceiv
> Fixes: 915fbe59cbf2 ARM: dts: imx: Add missing #phy-cells to usb-nop-xceiv
> Link: https://marc.info/?l=linux-usb&m=151518314314753&w=2
> Link: https://patchwork.kernel.org/patch/10158145/
> Cc: stable at vger.kernel.org
> Cc: Stefan Wahren <stefan.wahren@i2se.com>
> Cc: Felipe Balbi <balbi@kernel.org>
> Cc: Eric Anholt <eric@anholt.net>
> Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
> Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>

> ---
>  drivers/phy/phy-core.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index b4964b067aec..8f6e8e28996d 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -410,6 +410,10 @@ static struct phy *_of_phy_get(struct device_node *np, int index)
>  	if (ret)
>  		return ERR_PTR(-ENODEV);
>  
> +	/* This phy type handled by the usb-phy subsystem for now */
> +	if (of_device_is_compatible(args.np, "usb-nop-xceiv"))
> +		return ERR_PTR(-ENODEV);
> +
>  	mutex_lock(&phy_provider_mutex);
>  	phy_provider = of_phy_provider_lookup(args.np);
>  	if (IS_ERR(phy_provider) || !try_module_get(phy_provider->owner)) {
> -- 
> 2.9.0
>

^ permalink raw reply

* EDAC driver for ARMv8 L1/L2 cache
From: Mark Rutland @ 2018-01-12 17:38 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <VI1PR04MB2078B4491702765BA546C5539A170@VI1PR04MB2078.eurprd04.prod.outlook.com>

On Fri, Jan 12, 2018 at 05:17:54PM +0000, York Sun wrote:
> On 01/12/2018 09:13 AM, Borislav Petkov wrote:
> > On Fri, Jan 12, 2018 at 04:48:05PM +0000, York Sun wrote:
> >> I see Stratix10 has A53 core. I am concerned on reading the
> >> CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
> >> registers. They may not be available on all SoCs, or all time.
> > 
> > Is there something like CPUID on x86, on ARM64 which denotes presence of
> > a certain feature?
> > 
> > Or is that thing devicetree?
> 
> This feature is available on the SoC I am working on (NXP LS1046A). It
> seems always there. I don't know if there is any register denoting the
> existence of such feature.

There is no architectural register describing this.

Judging by the Cortex-A53 TRM, there is no IMP DEF / auxilliary register
describing this.

Regardless, a DT binding is necessary due to potential interactions with
FW, hypervisors, etc.

> I guess we can use device tree if this feature exists. Not sure if
> big.LITTLE is a concern here.

There are big.LITTLE systems with Cortex-A53, so we definitely care
about big.LITTLE here.

Thanks,
Mark.

^ permalink raw reply

* EDAC driver for ARMv8 L1/L2 cache
From: Thor Thayer @ 2018-01-12 17:39 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <VI1PR04MB20786CC3E2981C0F60E095079A170@VI1PR04MB2078.eurprd04.prod.outlook.com>

On 01/12/2018 10:48 AM, York Sun wrote:
> On 01/12/2018 08:35 AM, Thor Thayer wrote:
>> On 01/09/2018 03:51 PM, York Sun wrote:
>>> On 01/09/2018 01:43 PM, Borislav Petkov wrote:
>>>> Adding some more people to CC.
>>>>
>>>> On Tue, Jan 09, 2018 at 08:48:43PM +0000, York Sun wrote:
>>>>> Borislav,
>>>>>
>>>>> Are you aware of any existing (or in development) EDAC driver for ARMv8
>>>>> L1/L2 cache? I am thinking to write one if not available yet.
>>>>
>>>> no I'm not but I see two EDAC drivers for ARM64: thunderx and xgene.
>>>>
>>>> Please synchronize with their authors and ARM people what would be the
>>>> best thing to do and try extracting shared functionality from them
>>>> into a common compilation unit instead of duplicating it. I don't want
>>>> separate drivers per functional unit.
>>>>
>>>
>>> Thanks for the pointer. Thunderx and xgene's drivers have different
>>> implementation on the hardware. I found one patch closer to what I
>>> expect, https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F7513231%2F&data=02%7C01%7Cyork.sun%40nxp.com%7C29cd81c44431418e2a6308d559da7d3b%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636513717317947616&sdata=flIZL8mxGc4VWbTpl5nPjkRXaB8uNjcc382HcXO08qE%3D&reserved=0. I don't see
>>> activities after 2015. I will reach out to the author.
>>>
>>> York
>>>
>>
>> Hi York,
>>
>> I'll be adding EDAC support for our Stratix10 (Quad ARM Cortex A-53) at
>> some point but I'm not sure when it is scheduled - probably in the next
>> few months. I'll be going through the same process of comparing our
>> architecture to others. Below are links to the Stratix10.
>>
> 
> I see Stratix10 has A53 core. I am concerned on reading the
> CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
> registers. They may not be available on all SoCs, or all time. The
> CPUMERRSR_EL1 needs to be read on each core, the L2MERRSR_EL1 needs to
> be read on each cluster. I am not sure how to handle them in EDAC driver
> yet. I am hoping Mark Rutland can shed some light as he commented on
> similar patches [1][2] before.
> 
> York
> 
> [1] https://patchwork.kernel.org/patch/7460391/
> [2] https://patchwork.kernel.org/patch/7513231/

I haven't started digging into EDAC for the Stratix10 yet so I don't 
have a comment but I'll check out your links. Thanks!

> --
> To unsubscribe from this list: send the line "unsubscribe linux-edac" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

^ permalink raw reply

* EDAC driver for ARMv8 L1/L2 cache
From: York Sun @ 2018-01-12 17:44 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180112173802.kb32zrxc5uhsjlxk@lakrids.cambridge.arm.com>

On 01/12/2018 09:38 AM, Mark Rutland wrote:
> On Fri, Jan 12, 2018 at 05:17:54PM +0000, York Sun wrote:
>> On 01/12/2018 09:13 AM, Borislav Petkov wrote:
>>> On Fri, Jan 12, 2018 at 04:48:05PM +0000, York Sun wrote:
>>>> I see Stratix10 has A53 core. I am concerned on reading the
>>>> CPUMERRSR_EL1 and L2MERRSR_EL1. The are IMPLEMENTATION DEFINED
>>>> registers. They may not be available on all SoCs, or all time.
>>>
>>> Is there something like CPUID on x86, on ARM64 which denotes presence of
>>> a certain feature?
>>>
>>> Or is that thing devicetree?
>>
>> This feature is available on the SoC I am working on (NXP LS1046A). It
>> seems always there. I don't know if there is any register denoting the
>> existence of such feature.
> 
> There is no architectural register describing this.
> 
> Judging by the Cortex-A53 TRM, there is no IMP DEF / auxilliary register
> describing this.
> 
> Regardless, a DT binding is necessary due to potential interactions with
> FW, hypervisors, etc.
> 
>> I guess we can use device tree if this feature exists. Not sure if
>> big.LITTLE is a concern here.
> 
> There are big.LITTLE systems with Cortex-A53, so we definitely care
> about big.LITTLE here.
> 

For a given system, for example A72-A53 big.LITTLE configuration, the
feature is known and can be described in DT. We have to detect which
core is running to determine if this feature is available. Does this
sound right?

York

^ permalink raw reply

* [PATCH] usb: xhci-mtk: fix semicolon.cocci warnings
From: kbuild test robot @ 2018-01-12 17:46 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <201801130146.PhKGTuzk%fengguang.wu@intel.com>

From: Fengguang Wu <fengguang.wu@intel.com>

drivers/usb/host/xhci-mtk.c:311:2-3: Unneeded semicolon


 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: a2ecc4df9f84 ("usb: xhci-mtk: supports remote wakeup for mt2712 with two xHCI IPs")
CC: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
---

 xhci-mtk.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -308,7 +308,7 @@ static void usb_wakeup_ip_sleep_set(stru
 		break;
 	default:
 		return;
-	};
+	}
 	regmap_update_bits(mtk->uwk, reg, msk, val);
 }
 

^ permalink raw reply

* [PATCH] usb: dwc2: Fix endless deferral probe
From: Mauro Carvalho Chehab @ 2018-01-12 17:51 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAK8P3a3yZKnBM9gD-0YiHdMuHXUV=11vxGgFsZvQSkbM=B5Mxw@mail.gmail.com>

Em Fri, 12 Jan 2018 10:18:59 +0100
Arnd Bergmann <arnd@arndb.de> escreveu:

> On Fri, Jan 12, 2018 at 9:06 AM, Stefan Wahren <stefan.wahren@i2se.com> wrote:
> > Am 12.01.2018 um 00:32 schrieb Arnd Bergmann:  
> >> On Wed, Jan 10, 2018 at 1:15 PM, Stefan Wahren <stefan.wahren@i2se.com>  
> 
> >> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> >> index b4964b067aec..93b55fb71d54 100644
> >> --- a/drivers/phy/phy-core.c
> >> +++ b/drivers/phy/phy-core.c
> >> @@ -410,6 +410,10 @@ static struct phy *_of_phy_get(struct device_node
> >> *np, int index)
> >>          if (ret)
> >>                  return ERR_PTR(-ENODEV);
> >>
> >> +       /* This phy type handled by the usb-phy subsystem for now */
> >> +       if (of_device_is_compatible(np, "usb-nop-xceiv"))
> >> +               return ERR_PTR(-ENODEV);
> >> +
> >>          mutex_lock(&phy_provider_mutex);
> >>          phy_provider = of_phy_provider_lookup(args.np);
> >>          if (IS_ERR(phy_provider) || !try_module_get(phy_provider->owner))
> >> {  
> >
> >
> > I tried this, but it doesn't work. "np" is the node of the USB controller,
> > not of the phy?  
> 
> Correct, that was a really dumb mistake on my end, I'm glad I asked
> you to try it first.
> 
> I'll fix it up and send the right version with a proper changelog right away.

I suspect you meant to do, instead:


diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index b4964b067aec..584cc1469f7d 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -410,6 +410,10 @@ static struct phy *_of_phy_get(struct device_node *np, int index)
 	if (ret)
 		return ERR_PTR(-ENODEV);
 
+       /* This phy type handled by the usb-phy subsystem for now */
+       if (of_device_is_compatible(args.np, "usb-nop-xceiv"))
+		return ERR_PTR(-ENODEV);
+
 	mutex_lock(&phy_provider_mutex);
 	phy_provider = of_phy_provider_lookup(args.np);
 	if (IS_ERR(phy_provider) || !try_module_get(phy_provider->owner)) {


(e. g. args.np, instead of np).

The above works for me on RPi3:

$ uname -a
Linux raspberrypi 4.15.0-rc7-mcc+ #28 SMP Fri Jan 12 12:35:19 EST 2018 armv7l GNU/Linux

$ lsusb
Bus 001 Device 005: ID 045e:0750 Microsoft Corp. Wired Keyboard 600
Bus 001 Device 004: ID 0572:960c Conexant Systems (Rockwell), Inc. DVBSky S960C DVB-S2 tuner
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

So, if you change np -> args.np, feel free to add my:

Tested-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Regards,
Mauro

^ permalink raw reply related

* [PATCH v3] rcutorture: Add basic ARM64 support to run scripts
From: Paul E. McKenney @ 2018-01-12 17:52 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515751892-37470-1-git-send-email-lianglihao@huawei.com>

On Fri, Jan 12, 2018 at 06:11:32PM +0800, lianglihao at huawei.com wrote:
> From: Lihao Liang <lianglihao@huawei.com>
> 
> This commit adds support of the qemu command qemu-system-aarch64
> to rcutorture.
> 
> Signed-off-by: Lihao Liang <lianglihao@huawei.com>

This is to replace your previous patch, not to apply on top of it,
correct?  (Either way is fine, just please let me know.)

							Thanx, Paul

> ---
> 
> Comparing to the previous version, this patch lifts the limitation of
> maximum 8 CPUs of option "-M virt" by adding "gic-version=host" to it.
> This allows qemu to use the maximum CPU number supported by the actual
> hardware.
> 
> This commit is against RCU's git branch rcu/dev
> 
> commit 505b61b2ec1d ("EXP: rcu: Add debugging info to other assertion")
> 
> 
>  tools/testing/selftests/rcutorture/bin/functions.sh | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
> index 07a1377..65f6655 100644
> --- a/tools/testing/selftests/rcutorture/bin/functions.sh
> +++ b/tools/testing/selftests/rcutorture/bin/functions.sh
> @@ -136,6 +136,9 @@ identify_boot_image () {
>  		qemu-system-x86_64|qemu-system-i386)
>  			echo arch/x86/boot/bzImage
>  			;;
> +		qemu-system-aarch64)
> +			echo arch/arm64/boot/Image
> +			;;
>  		*)
>  			echo vmlinux
>  			;;
> @@ -158,6 +161,9 @@ identify_qemu () {
>  	elif echo $u | grep -q "Intel 80386"
>  	then
>  		echo qemu-system-i386
> +	elif echo $u | grep -q aarch64
> +	then
> +		echo qemu-system-aarch64
>  	elif uname -a | grep -q ppc64
>  	then
>  		echo qemu-system-ppc64
> @@ -176,16 +182,20 @@ identify_qemu () {
>  # Output arguments for the qemu "-append" string based on CPU type
>  # and the TORTURE_QEMU_INTERACTIVE environment variable.
>  identify_qemu_append () {
> +	local console=ttyS0
>  	case "$1" in
>  	qemu-system-x86_64|qemu-system-i386)
>  		echo noapic selinux=0 initcall_debug debug
>  		;;
> +	qemu-system-aarch64)
> +		console=ttyAMA0
> +		;;
>  	esac
>  	if test -n "$TORTURE_QEMU_INTERACTIVE"
>  	then
>  		echo root=/dev/sda
>  	else
> -		echo console=ttyS0
> +		echo console=$console
>  	fi
>  }
> 
> @@ -197,6 +207,9 @@ identify_qemu_args () {
>  	case "$1" in
>  	qemu-system-x86_64|qemu-system-i386)
>  		;;
> +	qemu-system-aarch64)
> +		echo -machine virt,gic-version=host -cpu host
> +		;;
>  	qemu-system-ppc64)
>  		echo -enable-kvm -M pseries -nodefaults
>  		echo -device spapr-vscsi
> @@ -254,7 +267,7 @@ specify_qemu_cpus () {
>  		echo $2
>  	else
>  		case "$1" in
> -		qemu-system-x86_64|qemu-system-i386)
> +		qemu-system-x86_64|qemu-system-i386|qemu-system-aarch64)
>  			echo $2 -smp $3
>  			;;
>  		qemu-system-ppc64)
> -- 
> 2.7.4
> 

^ permalink raw reply

* [PATCH][v2] arm64: Allocate elfcorehdr & crashkernel mem before any reservation
From: James Morse @ 2018-01-12 17:58 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <DB5PR0401MB1733C9CB0DCDF94FCF3E4E1286130@DB5PR0401MB1733.eurprd04.prod.outlook.com>

Hi Poonam,

On 08/01/18 04:31, Poonam Aggrwal wrote:
> James Morse wrote:
>> On 04/01/18 15:34, Poonam Aggrwal wrote:
>>> Address for both crashkernel memory and elfcorehdr can be assigned
>>> statically. For crashkernel memory it is via crashkernel=SIZE at ADDRESS
>>> and elfcorehdr_addr via by kexec-utils in dump kernel device tree.
>>
>> There are some crashkernel=SIZE at ADDRESS values that the user can supply that
>> we must reject. The obvious one is if it overlaps with the kernel text. (this patch
>> won't spot this). We need to read the hardware's reserved regions from the DT
>> before we allocate the crashkernel region, for example if the bootloader
>> reserved a chunk of memory for a frame-buffer, I shouldn't be able to use that
>> as crashkernel memory.
>>
>> (you shouldn't need to specify an address, doing so prevents the kernel from
>> picking memory it can use)
>>
>>
>>> So memory should be reserved for both the above areas before any other
>>> memory reservations are done. Otherwise overlaps may happen and memory
>>> allocations will fail leading to failure in booting the dump capture
>>> kernel.

>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index
>>> 00e7b90..24ce15d 100644
>>> --- a/arch/arm64/mm/init.c
>>> +++ b/arch/arm64/mm/init.c
>>> @@ -453,6 +453,14 @@ void __init arm64_memblock_init(void)

>>> +	reserve_elfcorehdr();
>>
>> (Moving reserve_elfcorehdr() makes sense, but..)
>>
>>
>>> +	reserve_crashkernel();
>>
>> reserve_crashkernel() does the allocation for the crashkernels reserved memory.
>> I expect this to always fail in the kdump kernel because there isn't enough
>> memory. (fdt_enforce_memory_region() at the top of this function calls
>> memblock_cap_memory_range()).
>>
>> Moving this allocation above the early_init_fdt_scan_reserved_mem() below
>> means we may allocate memory for the crashdump that is in use by
>> firmware/hardware and described as reserved in the DT.

> Yeah, this is a good point. So ideally the address of the crash kernel should
> be diligently provided by the user based on the system.

Even better: the region to store the crash kernel in should be chosen by the kernel.
When using kdump I boot with 'crashkernel=1G', the kernel chooses where to place
the reserved region. Even if I specified a reasonable physical address, the
efistub may relocate the kernel over the top during boot as part of its KASLR work.

(Why does anyone ever need to specify an offset here?)


Thanks,

James

^ permalink raw reply

* [PATCH v3 12/13] arm64: Implement branch predictor hardening for Falkor
From: Shanker Donthineni @ 2018-01-12 17:58 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1515432758-26440-13-git-send-email-will.deacon@arm.com>


Hi Will,
 

This patch is the right one for variant2, checks QDF2400 part numbers QCOM_FALKOR and FALKOR_V1
but unfortunately it got modified and merged to linux-next branch causing confusion.Please revert
and merge [V2] patch to fix the problem.
 
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/arch/arm64?h=next-20180112&id=ec82b567a74fbdffdf418d4bb381d55f6a9096af

[v2] https://www.spinics.net/lists/arm-kernel/msg627364.html


Thanks,
Shanker

On 01/08/2018 11:32 AM, Will Deacon wrote:
> From: Shanker Donthineni <shankerd@codeaurora.org>
> 
> Falkor is susceptible to branch predictor aliasing and can
> theoretically be attacked by malicious code. This patch
> implements a mitigation for these attacks, preventing any
> malicious entries from affecting other victim contexts.
> 
> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
> [will: fix label name when !CONFIG_KVM]
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/include/asm/cpucaps.h |  3 ++-
>  arch/arm64/include/asm/kvm_asm.h |  2 ++
>  arch/arm64/kernel/bpi.S          |  8 +++++++
>  arch/arm64/kernel/cpu_errata.c   | 49 ++++++++++++++++++++++++++++++++++++++--
>  arch/arm64/kvm/hyp/entry.S       | 12 ++++++++++
>  arch/arm64/kvm/hyp/switch.c      | 10 ++++++++
>  6 files changed, 81 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
> index 51616e77fe6b..7049b4802587 100644
> --- a/arch/arm64/include/asm/cpucaps.h
> +++ b/arch/arm64/include/asm/cpucaps.h
> @@ -43,7 +43,8 @@
>  #define ARM64_SVE				22
>  #define ARM64_UNMAP_KERNEL_AT_EL0		23
>  #define ARM64_HARDEN_BRANCH_PREDICTOR		24
> +#define ARM64_HARDEN_BP_POST_GUEST_EXIT		25
>  
> -#define ARM64_NCAPS				25
> +#define ARM64_NCAPS				26
>  
>  #endif /* __ASM_CPUCAPS_H */
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index ab4d0a926043..24961b732e65 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -68,6 +68,8 @@ extern u32 __kvm_get_mdcr_el2(void);
>  
>  extern u32 __init_stage2_translation(void);
>  
> +extern void __qcom_hyp_sanitize_btac_predictors(void);
> +
>  #endif
>  
>  #endif /* __ARM_KVM_ASM_H__ */
> diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S
> index dec95bd82e31..76225c2611ea 100644
> --- a/arch/arm64/kernel/bpi.S
> +++ b/arch/arm64/kernel/bpi.S
> @@ -77,3 +77,11 @@ ENTRY(__psci_hyp_bp_inval_start)
>  	ldp	x0, x1, [sp, #(16 * 8)]
>  	add	sp, sp, #(8 * 18)
>  ENTRY(__psci_hyp_bp_inval_end)
> +
> +ENTRY(__qcom_hyp_sanitize_link_stack_start)
> +	stp     x29, x30, [sp, #-16]!
> +	.rept	16
> +	bl	. + 4
> +	.endr
> +	ldp	x29, x30, [sp], #16
> +ENTRY(__qcom_hyp_sanitize_link_stack_end)
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index cb0fb3796bb8..7b4efde087fc 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -54,6 +54,8 @@ DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
>  
>  #ifdef CONFIG_KVM
>  extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[];
> +extern char __qcom_hyp_sanitize_link_stack_start[];
> +extern char __qcom_hyp_sanitize_link_stack_end[];
>  
>  static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
>  				const char *hyp_vecs_end)
> @@ -96,8 +98,10 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
>  	spin_unlock(&bp_lock);
>  }
>  #else
> -#define __psci_hyp_bp_inval_start	NULL
> -#define __psci_hyp_bp_inval_end		NULL
> +#define __psci_hyp_bp_inval_start		NULL
> +#define __psci_hyp_bp_inval_end			NULL
> +#define __qcom_hyp_sanitize_link_stack_start	NULL
> +#define __qcom_hyp_sanitize_link_stack_end	NULL
>  
>  static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
>  				      const char *hyp_vecs_start,
> @@ -138,6 +142,29 @@ static int enable_psci_bp_hardening(void *data)
>  
>  	return 0;
>  }
> +
> +static void qcom_link_stack_sanitization(void)
> +{
> +	u64 tmp;
> +
> +	asm volatile("mov	%0, x30		\n"
> +		     ".rept	16		\n"
> +		     "bl	. + 4		\n"
> +		     ".endr			\n"
> +		     "mov	x30, %0		\n"
> +		     : "=&r" (tmp));
> +}
> +
> +static int qcom_enable_link_stack_sanitization(void *data)
> +{
> +	const struct arm64_cpu_capabilities *entry = data;
> +
> +	install_bp_hardening_cb(entry, qcom_link_stack_sanitization,
> +				__qcom_hyp_sanitize_link_stack_start,
> +				__qcom_hyp_sanitize_link_stack_end);
> +
> +	return 0;
> +}
>  #endif	/* CONFIG_HARDEN_BRANCH_PREDICTOR */
>  
>  #define MIDR_RANGE(model, min, max) \
> @@ -302,6 +329,24 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
>  		MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
>  		.enable = enable_psci_bp_hardening,
>  	},
> +	{
> +		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
> +		.enable = qcom_enable_link_stack_sanitization,
> +	},
> +	{
> +		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
> +		.enable = qcom_enable_link_stack_sanitization,
> +	},
> +	{
> +		.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
> +	},
> +	{
> +		.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
> +		MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
> +	},
>  #endif
>  	{
>  	}
> diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
> index 12ee62d6d410..9c45c6af1f58 100644
> --- a/arch/arm64/kvm/hyp/entry.S
> +++ b/arch/arm64/kvm/hyp/entry.S
> @@ -196,3 +196,15 @@ alternative_endif
>  
>  	eret
>  ENDPROC(__fpsimd_guest_restore)
> +
> +ENTRY(__qcom_hyp_sanitize_btac_predictors)
> +	/**
> +	 * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700)
> +	 * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls
> +	 * b15-b0: contains SiP functionID
> +	 */
> +	movz    x0, #0x1700
> +	movk    x0, #0xc200, lsl #16
> +	smc     #0
> +	ret
> +ENDPROC(__qcom_hyp_sanitize_btac_predictors)
> diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
> index 4d273f6d0e69..7e373791fad1 100644
> --- a/arch/arm64/kvm/hyp/switch.c
> +++ b/arch/arm64/kvm/hyp/switch.c
> @@ -406,6 +406,16 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>  		/* 0 falls through to be handled out of EL2 */
>  	}
>  
> +	if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) {
> +		u32 midr = read_cpuid_id();
> +
> +		/* Apply BTAC predictors mitigation to all Falkor chips */
> +		if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
> +		    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) {
> +			__qcom_hyp_sanitize_btac_predictors();
> +		}
> +	}
> +
>  	fp_enabled = __fpsimd_enabled();
>  
>  	__sysreg_save_guest_state(guest_ctxt);
> 

-- 
Shanker Donthineni
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

^ permalink raw reply

* [PATCH v5 3/5] misc serdev: Add w2sg0004 (gps receiver) power control driver
From: H. Nikolaus Schaller @ 2018-01-12 17:59 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180112153903.GB5992@localhost>

Hi Johan,

> Am 12.01.2018 um 16:39 schrieb Johan Hovold <johan@kernel.org>:
> 
>> Let's restart this discussion and focus on the main roadblock (others
>> are minor details which can be sorted out later).
>> 
>> If it feels like a hack, the key issue seems to me to be the choice of
>> the API to present the GPS data to user space. Right?
> 
> Or even more fundamentally, does this belong in the kernel at all?

Yes, that can be questioned of course. It was questioned and discussed
several times and I thought the answer was a clear yes. But let's reiterate.

> 
> Also it seems at least part of your specific problem is that you have
> failed to wire up the WAKEUP pin of the W2SG0004/84 properly,

The w2sg0004 has no wakeup pin. At least I can't find one in the data sheet.

The two pins you refer to from the 0084 data sheet are called BootSelect0/1
in the 0004 and have a different function.

To be clear, we did not fail to wire it up. We did the design before the
0084 was announced and available. We just had to swap in the 0084 into
existing PCBs during production because the 0004 became EOL. Otherwise
we would probably still use the 0004 without WAKEUP output.

To make it worse, we have no documentation for an individual board if
an 0004 or 0084 chip is installed and there is no means how a software
can find out which one it is talking to (especially before properly
powering on). Therefore we can not even provide two different device
trees or drivers or whatever, unless we ask people to open their device
and look on the chip. Quite crazy wrt. user-friendlyness of software
installation in 2018...

Therefore, a driver must be capable to handle both chips in the same way,
with minimalistic assumptions, even if the 0084 could provide a direct
signal to make it easier than using serdev to monitor the data stream.

>  which then
> forces you to look at the data stream to determine the power state of
> the chip. Judging from a quick look at the GTA04 schematics it seems
> you've even connected the WAKEUP output to the 1V8_OUT output?!

No. You failed to see that this is an optional 0R, which is not installed.
The 0R on pin 7 (BootSelect1) to GND was removed when we did switch from
0004 to 0084. Pin 6 (BootSelect0/WAKEUP) was never connected.

> The kernel is probably not the place to be working around issues like
> that,

You appear to assume this our only motivation is to make a workaround for
a hardware design flaw but that isn't.

The purpose of the driver is to provide power management for the GPS
subsystem which happens to be based on a chip with limited functionality.

And the serdev thing is the solution, not the requirement...

> even if serdev at least allows for such hacks to be fairly
> isolated in drivers (unlike some of the earlier proposals touching core
> code).

Please tell me why there are so many hacks for hardware issues in certain
drivers. Any why those are good and this one (if it is one at all) is not.

Some picks random fgrep -iR hack drivers

drivers/char/random.c: * Hack to deal with crazy userspace progams when they are all trying
drivers/clk/meson/meson8b.c:	 * a new clk_hw, and this hack will no longer work. Releasing the ccr
drivers/clk/samsung/clk-exynos3250.c:	/* HACK: fin_pll hardcoded to xusbxti until detection is implemented. */
drivers/gpu/drm/amd/amdkfd/kfd_events.c:	 * This hack is wrong, but nobody is likely to notice.
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:		 * HACK: IGT tests expect that each plane can only have one
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:	/* It's a hack for s3 since in 4.9 kernel filter out cursor buffer
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:		/* TODO This hack should go away */
drivers/gpu/drm/amd/display/dc/core/dc_link.c:	/* A hack to avoid failing any modes for EDID override feature on

What I can learn from your discussion is that it might be considerable
to add an optional gpio for the 0084 WAKEUP and add some logic to
support users who have or will have that pin connected.

But even then we would need a driver to handle this gpio and issue
an on/off impulse on the other to switch states. It would be a different
driver (variant - maybe some CONFIG option or handled by code), but not
"no driver".

> 
>> I see three reasonable options how this presentation can be done:
>> 
>> 1. char device
>> 2. tty device
>> 3. some new gps interface API (similar to network, bluetooth interfaces)
>> 4. no driver and use the UART tty directly
>> 
>> Pros and cons:
> 
>> 4. no driver and use UART directly
>> + a non-solution seems to be attractive
>> - must turn on/off chip by gpio hacks from user-space
> 
> I'm not sure that would amount to more of hack then doing it in the
> kernel would.

It might not be big effort in the user-space code/scripts.

But much effort to convince all the plethora of user-space client maintainers
to integrate something. And have them roll out. And have distributions take it.
And have users upgrade to it. 5 years later...

Do you think it is easier to convince them than you? They usually assume a
power management issue should be solved by the kernel driver.

That is what Andreas did remark as motivation: provide a solution
for *existing* user spaces.

> 
>> - can not guarantee (!) to power off the chip if the last user-space
>> process using it is killed (which is essential for power-management of
>> a handheld, battery operated device)
> 
> That depends on how you implement things (extending gpsd, wrapper
> script, pty daemon, ...).

No. You can of course cover all standard cases but there is one fundamental
issue which is IMHO a problem of any user-space implementation:

	How can you guarantee that the chip is powered off if no
	user-space process is using it or if the last process doing
	this is killed by *whatever* reason?

E.g. after a kill -9. Or if someone deinstalls gpsd or whatever and assumes
(and wants a guarantee) that GPS is now turned off and never turned on drawing
precious milliamps from the battery for no use.

As it is well known, a user-space process can't protect itself against kill -9.
Or has this recently been changed and I am not aware of?

This is the fundamental reason why we need a kernel driver to provide
reliable, repeatable and trustable power management of this chip.

It is equally fundamental as a hard disk should spin down after the last
file is closed. Even if this process ends by a kill -9.

A second almost equally fundamental aspect to be considered is how you want
to automatically and reliably turn off the chip by pure user-space code when
entering suspend.

> 
> 
>> I would clearly prefer 3 over 2 over 1 over 4.
>> 
>> So do you see a chance that the kernel core team provides something useable
>> (not perfect) for variant 3 in reasonable time (let's say 3-6 months)?
> 
> No, I'm afraid not. At least not if we're talking about a framework
> that would replace gpsd.

This confirms my assumption that there is nothing really good to expect
soon to implement a driver for variant 3.

> 
>> If not, I want to suggest to accept the second-best choice 2. for now and we
>> will update the driver as soon as 3. appears. IMHO it would be a good test case
>> for a new subsystem.
> 
> Getting the interface right from the start is quite important, as
> otherwise we may end up having to support a superseded one for a long
> time.

This seems to contradict your argument that user-space can very easily
adapt to everything. If the latter were true there would be no need to
keep old interfaces supported for a long time.

So can you agree to that a battery powered portable device must have
reliable and trustable power management? And if it provable can't be
implemented in user-space (a single counter example suffices) it must
be a kernel driver?

BR,
Nikolaus

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